The thing is, look at the bike and ask yourself if it adds to your collection in an enjoyable way, or it has something you need to complete a bike core to your collection. Some people collect one type of bike but look for different subtypes, some collect wildly different bikes because they like the variety, some have many bikes, some have far fewer. Be careful not to fall into the trap of buying it solely because it seems cheap. You're in for a world of hurt if you stock up on garage sale bikes only to find they're not adding much to your collection or they're just kind of "meh" when you ride them. I don't mean to be discouraging anyone, but I do mean to encourage being selective with your time, space, and money. I have two 1970s Raleighs I love and that ride well. I wouldn't want 4 or 5 duplicates of them though, pulled from various garages. A selective mindset is good once you get beyond the first bike or two. Don't be afraid to sell off if they aren't adding much to your collection as well.