When I had more money coming in, I got spoiled with the quilt shop quality of fabric. But locally, it's about $12-14/yard now. I started shopping around and now I find some really great sales. Stores vary, I shop at many different places, mostly ones I discovered on
www.quiltshops.com . I signed up for newsletters for some of my favorite shops and watch for sales. Some places have lower prices all the time, like Thousands of Bolts and Marshall Dry Goods. Some have lower than average everyday prices, and great clearance, like Over the Rainbow. I've gotten brand name fabrics for as low as $4.00/yd. I do shop at Joann's sometimes, but I get better quality fabrics for less money at other places usually. My local Joann's is a mess and I don't care to shop there.
For batting, I like Hobb's 80/20, which I can get very reasonable at Connecting Threads (when it's on sale) or Michael's (coupon). I usually grab a queen size, which is often on sale around $12-13.
Thread can be expensive. Many people like the Connecting Threads brand. Personally I don't. I tried it a few years ago and was disappointed. Bought some last month to try again and am still disappointed. I use Aurifil mostly. I shop around for that too since prices can vary from about $8-13 for a large spool. Fil-tec/Bobbin Central has a nice cotton thread called Cairo-quilt. It is very similar to Aurifil, but about 1/2 the price. The only thing about them is they just increased the minimum order to $50. If you can get a couple of people together and all order a couple of things, it's not so bad though.