Should I tip at a garage sale?

Although I have been living in Ontario for almost 4 years, never really cared a lot about garage sales.

However, I recently became a father and found that some garage sales are great for baby/infant stuff. And I was really surprised to find 100+ dollars toys being sold for 10 or 5 dollars only.

Are these prices that low because they are expecting a tip? Or this is just part of the tradition to get rid of old stuff and prices are not really important?