I don't think I ever scored something good at a garage sale or estate sale. Maybe it is because I get up late on weekends? I'd kill myself if I had to wear those TABS shoes, so that's probably why.
Shoes are one area (unlike guns), where synthetic materials certainly have helped to improve the experience.
My wife likes hosting garage sales. Always have to put in the ad "no early birds", otherwise, you'll have some ahole ringing your door bell at 6 am wanting to see if you had tools, watches or jewelery - looking for that first dibs. Of course all we usually have is total junk the thrift store won't take.
G