The comments here are misleading...they are worth $2. You can get them anywhere, if they were discontinued maybe but even then there is so much in circulation that would even be a stretch. Save it, spend it, invest with it, or gamble it....just as you would with your other fiat
This is true in general, yes. But if you have rare ones, they can be worth more. I don't know off the top of my head which bills are rare, but I know some $1s, for example, are worth hundreds of thousands because of specific serial numbers and stuff. Or misprints.