Look up how much it would cost to ship that stuff to help you decide! Shipping can be EXTREMELY prohibitive cost-wise, and for cheaper stuff it often isn't worth it, but you're the only one who can decide if it's worth it to you, or how often it'd be worth it. I ship books, but shipping prints and posters wasn't worth it to me.
If you're shipping through the US postal service, you can look up how much shipping would cost here -- weigh the thing you want to send and the packaging you would send it in, and see how much it'd cost you to send to different parts of the US. (When I was considering what I wanted to use for shipping, I actually went to the post office with a book, waited in line, and just asked them "how much would it cost to mail this?" and they weighed it for me) And consider what you'd do when you end up with a sub or contest winner who isn't in the US -- this is the internet, it's very easy to end up with non-US readers, but international shipping rates are VERY HIGH.