Sometimes I shop for my quilt fabric at the thrift store. Sometimes I find shirts and skirts that look brand new. Sometimes I buy them for 50 cents or a dollar. Usually a shirt or skirt has more than a fat quarter in it.
I've never been a person devoted to the newest, the most modern, or the most stylish, so I don't mind that I'm not buying the most popular designer quilting fabrics.
Before I buy anything at the thrift store I take a whiff of it. If there's the least scent of mildew or age it stays at the store. If I smell fabric softener I know that will wash out, but it's nearly impossible to get rid of the mildew and age odors.
Immediately upon arriving in my home I remove the tags and toss the clothes in the dryer for 20 minutes. Bedbugs are not welcome at my house.
The next order of business is to soak them in the washer to remove "human" odors. I use the lowest water level setting and use the hottest water that's safe for the clothes. I add 1/2 cup salt and 1 cup of vinegar. The clothes rest in the water for at least 30 minutes. Then I add regular laundry soap/detergent, more water, and wash as usual.
About 10 years ago I saw plaid fabrics used for quilts in Roberta Horton's book, Scrap Quilts: The Art of Making Do. The fabric stores didn't have many plaids but the thrift stores had wonderful, nearly new plaid shirts for 50 cents. I was on my way. I still have plenty of plaids which I don't hesitate to mix with prints and plains.
I credit Roberta Horton's book with my foray into thrift store fabric shopping.