Selling a piece and other shenanigans

So someone (a friend, but still) asked to buy one of my instax photos. This one, to be exact:

Now I have no problems selling this (after I get a better scan of it from the big DAAP scanners, not my little HP)... but I have no idea what to price it. Especially between friends. Suggestions? It is a VERY small photo, about the size of a credit card.

In other news, I finally got around to scanning some of the daily comics I've been doing, so they're all available on my tumblr. (Also on my tumblr, continuing work on my YouTube photography.)

Check them out! (Click!)