As a poor doctoral student, let me first say that I feel your pain when it comes to how much things cost. And we get the idea that you don't have much money, as you mention it in nearly every post.
As for what you need, you seem to have some unrealistically high demands. Beginning with the case cover...the oboe one listed for sale for $35 has no relevance to bassoon covers. Ours are at least twice as much material. When you factor in stitching one together, the materials, the time, and the expertise it takes to make covers, $35 is unbelievable low. And most people sell the case covers with the case when they sell either the case/cover separately or with an instrument. From what I've seen as I've been around, people use their covers until they're basically worn out. If your price is firm, then you may need to consider making it yourself, or with one of your parents' help if either of them sew.
Reed cases are the same situation. If they are as simple as you say they are to make based on a previous post of yours, consider making one. If finances really are a problem, get a couple of plastic Fox reed cases. Drill some ventilation holes in them. They're pretty reliable, last a long time, and are very functional. Other than that, check out forrestmusic.com and charlesmusic.com (I think those are the websites). One of them, and I forget which one, has a case that holds 10 reeds for around $40. I've never seen an overall better value than that. But it does not use mandrel tips for holders. That bothers some people. But I've had a teacher and a masters bassoon colleague that have used this case and they love it.
Bassoon stands are not cheap. The expense lies in the molds that they use to make they pieces, or the high quality but lightweight metal they use, and the craftsmanship. There are options out there. Research them. If you can't afford one, then you can't afford one. I think I've only know two or three people that had a bassoon stand while they were still in high school. Get over it. And keeping a bassoon on a stand long-term is not the best idea. Look up the IDRS article about Ron Klimko leaving his bassoon together while he went skiing. If not being played, the best place for your bassoon to be is swabbed out and placed in the case.
Swabs are also expensive for the amount of material you get, until you look a little deeper. You need to know how much silk to use, have an idea of the type of pull through attachment you want, and to get the nicely put together look that we all like, you need a serger, which is a special type of sewing machine, which can run upwards of $1000 if you get an industrial model. When I was just out of high school I made a swab with some help from a woman who could sew. I bought cotton fabric, cut it to size, attached a shoelace to which I added a small lead or aluminum weight. I used it for a couple of years, until the threading pulled so much that it became a problem. At that point I bought a swab. I think I recall seeing a bocal swab for around $10, but I may be remembering that incorrectly, so I suggest you look it up. Until then, a brush swab (called a bocal snake) can be used. I've also run warm water through the sink, added a tiny bit of liquid soap, shaken it up alot, and then flushed my bocal. It may not be fancy, but it will do in a pinch. And that is the most economical alternative.
Used tools can be found occasionally. Keep checking on the classifieds link from the forum. Sometimes people sell used tools there. Also check ebay. I regularly see mandrels, including throat mandrels, for sale there. I bought a set a couple of years ago of one regular and one throat mandrel for around $15. For me and my level of woodworking skills, I couldn't beat that bargain. But remember that someone has to make our tools. That also requires expertise. Skills on working with the metal to shape it, sharpen it, and be good enough at it to market them for a relatively competitive cost. Same for plaques, lighted or otherwise. The lighted ones might be great, but I've only ever seem them at conventions or on websites, and I've had one in my had for about a minute. If even $30 is prohibitive, don't buy one. Regular plaques get the job done too. If you really need to see through one, get a clear one from Justin Miller. Held up to a strong light, you can see through them enough to make do. And those are relatively new in the last few years, so most of us have used the good old plaques. I think Justin's clear one is around $4, and the basic Fox metal plaque I picked up at a double reed day for around $10, but they might be more ordered from a website.
If you really want a wooden music stand but can't spend that much, consider making it yourself. Or go buy one of those portable metal fold-up stands. Those you might even come across at garage sales.
I don't happen to care for the shape of the plastic Fox crutches either. Contact them through their website to order a different one (wooden even), or take your chances from ebay. The players that use crutches usually have very specific ones that they use if they're not using a basic one. Those are not likely to be parted with. And it really does matter about the shape of you hand and how you hold the bassoon. New, ebay or otherwise, is likely your best bet.
Regarding neck straps and balance hangers: there are a variety of devices to use while standing. And you either buy it sight unseen or try someone else's or while at a display. University level teachers might have several types that you could try, but most of us buy what feels right for us, and then we occasionally move on if we find something we like better. Finding one used is really a hit or miss game. I think in the years that I've been looking for stuff like this, I've only seen one or two balance hangers. One was purchased and never installed, and one was a design that make me think buying a Fox balance hanger would work better on my Fox bassoon than that one. And it really is about balance...you have to find what works for you.
An important thing to remember is that we have all been poor college/high school students at some point in our lives. We know what that means. You need to remember that most of us are not independently wealthy, and we save for what we want/need, make do, or do without. I didn't get my own bassoon stand until my sixth year of my bachelor's degree. And I lucked into a situation. I didn't buy my first bassoon until after I had earned my bachelor's degree. I bought used, and got one hell of a deal on it. But I waited, and kept a meticulous watch on ebay, netinstruments.org, and bassoon.org (but the last one no longer lists instruments for sale). I checked these websites multiple times each day. And it was close to a year before I found a bassoon that I liked that I could afford (with help). All of these things are nice, but you do not need all of them now.
A bassoon case cover needs to fit your bassoon case, and it may not fit the case to a different brand. I even had a friend who, during my masters degree, was willing to lend me his old case since mine was having problems. His old case fit his 240, but my 201 did not fit his case. And the nicer cover he had didn't fit my case either. If you don't own your own bassoon, getting a case cover might work but might not. Do you want to take that chance?
What you need right now is probably a reed case or two (and I'm very impressed with a high schooler who has more than 3 or 4 usable reeds at one time anyway), a good swab for the tenor and boot joints (silk is good but cotton will do, and there's a newer material that I like better, but I can't remember what it is), and a basic set of tools: holding mandrel, reamer (maybe), forming mandrel (maybe), plaque, pliers, brass wire (maybe), wax (if you use it), a lighter for the wax, and a knife. The maybes are in case you do not make your own reeds yet.
Remember that you acquire tools a little bit at a time. Get what you need, then add what you want, including upgrading to nicer tools. Even though you've mentioned that your teacher is in college, he or she is in a better position to know how to help you with what you need. That includes wire and reaming. Try not to go over his or her head with your questions. I've done that myself a couple of times, and I've been called out on it. And that wasn't very pleasant. Your teacher might also have colleagues who are upgrading their tools. Those people might be willing to give you a deal. Get the equipment you need and want a little bit at a time. Save for it. Ask for some of this for Christmas and birthday gifts. This is how most of us get/have gotten what we need. And learn to use spellcheck.
I hope this is food for thought.