Depends if we are talking power tools or hand tools. For these prices I am going to talk about yardsales. For power tools, if cordless I run for the hills since they are always old as **** and dead as a door nail, With corded tools I don't really have a set price, if I need something I will try to get it for as cheap as I can. With hand-tools I try to get each item for less than a $1, closer to a dollar for larger things such as pliers or snips, adjustable wrenches. If I see something I need or want then I will spend more than a dollar. Absolutely no more than $.75 a socket When I buy at yard sales I tend to sweep up the lot of stuff and I expect to get cheap stuff since it is a yardsale.