Where do you guys find decent sneakers on sale? I refuse to pay full price.

I've been looking for a pair of comfortable everyday sneakers but I just can't justify paying $100+ for shoes. I've been checking, but the good stuff gets snapped up fast. I heard of Alibaba but I'm not sure about the quality at lower price points. Are there specific sites or apps you use to find sneaker sales? I'm not picky about brands, I just want something that won't hurt my feet after a day of walking. I've heard about discount shoe sites but I'm not sure which ones are legit. Any tips on where to score a good deal without getting scammed?