I don't even remember the last time I bought at full retail... I alway am happy to wait until fabrics go on clearance. The time difference between when a fabric line is brand new and when it will go out of print is about the same as the time it will sit in my stash before I use it... so what's the rush?
I live 6.5 hours away from Marshall's Dry Goods but I make at least two trips a year to go shop there. It's so much fun to dig through their flat folds and come away with great, but discontinued, LQS quality fabric for $3, and $4-5 on the bolt. Not all their fabric is LQS quality, but enough of it is that I keep going back.
I do a lot of charity quiltmaking, so I am always on the hunt for reasonably priced but good fabrics to use. I also buy my battings at Marshall's, on huge rolls.
I don't see much good fabric at estate sales, but when I do I snap it up. Cool vintage cottons are like treasure to me!