Yes! I've done that too... particularly for checks/plaids. I find the super duper 3x shirts in Goodwill's men's section for pennies. That and some women's skirts or denim dresses if you're doing a denim quilt. All good.
I once... ONCE... bought 5 yards of purple denim from a fabric store (not a LQS) only to have it run... and run... and run. Something like 15 washes later, with all kinds of additives, 'dye catchers' and the like.... it STILL runs, even though it's now a very light gray-lilac... with streaks. <sigh> Money wasted. Now, when I want denim for a quilt, I goto Goodwill/thrift stores and buy ladies jumper dresses. At least they are so well washed, they have great 'hand' and don't run!
So far, I've cut up that nasty lilac denim to use as seat covers for my stool, sewing bench and drafting chair in my sewing room. If/when they get dirty...I'll THROW them away and sew up new ones. I'm orn'ry enough to find SOMETHING to use that nasty fabric on.
okay... thanks for listening to me rant! lol