I've never really been to a lot of garage sales, but when they had the tag sales at church I'd pick up some games or things like that, got some antique bicycle horns once.
Spiders and I have an agreement. As long as they stay in their own area, and eat all the bugs they can catch, then we're fine and there's no problem. Once they invade my personal space, however, I have no other choice but to squish them.