I love thrift store shopping. I almost never buy retail, except for undergarments. If you can afford it, maybe there is nothing wrong with spending $10 whenever you lose another 10 lbs. I have lost 55 lbs this year, and I have enjoyed buying some fun stuff! Not a lot - I don't own a lot of clothes. At this point I only buy things I think are beautiful. I can walk out without buying anything, if there is nothing that strikes me as beautiful. I don't buy anything that is "good enough". I used to - I would walk into Walmart, see a shirt roughly my style, in a color I liked, and pay $10 for it. What a waste! Now I spend the same amount, but on things that I look good in.
I do still buy "good enough" shoes, though. I bought shoes yesterday at a thrift store. A pair of black maryjanes by Doc Martin ($20) in very good condition. A pair of black leather Naot sandals (division of Teva) for $5 in like new condition, and brown Naturalizer flats ($5) in good condition. The brown flats wil probably last a year, and are definitely just good enough. The others should last for several years.