My suggestion is don't rush to buy a saddle. Find one that fits you well and go for one that is a good quality leather. Name brand isn't as important. If you want to get a used one that is fine, just make sure it's in good shape. When you do get one (going off what and how you ride), make sure it has QH bars so that you can use it on several horses. With a narrower horse you would need a built up pad but I would think it would fit most western horses.
I agree that an ill fitting saddle (in this case for the rider) would effect your position and your ability to sink into the seat. Do I think you are being a spoiled brat? Heck no. I was there. I was that girl with no horse and no saddle. I wanted things and had no money to buy them. I know exactly how you feel. You'll get there. And when you do, it will probably be by your own means. Good luck.
Don't rush into the purchase of a saddle and try hard to ensure it's a good quality leather.