I never had a stash really, just odds and ends and leftovers. This year I started building one and I've made many fat quarter bundle purchases, one was 144 FQs on eBay. No, FQs alone don't go very far so unless I have the whole collection that can go together into a design then it will likely end up in a scrappy type quilt.
I just ordered some fabric yesterday from Whittle's Fabric online and at $3.50 to $4.50 per yard it only came to $90-something for 22 yards. I don't have anything specific in mind for them so I bought 1 yard each of most of them. I usually will get a set of fabrics in a collection, ALL of them if I can. I bought 2 yards each of one collection that there were only 4 fabrics of since I figure a full or queen size quilt in a simple pattern would be at least 8 yards plus border. I also will buy more of the "background" fabric, 3 or 4 yards.
Whittle's is just great, IMO. I placed the order yesterday morning and I got an email at 1:00 in the afternoon informing me that the order had shipped.