I'd bid up to $25 for a single drawing. Something I could frame on the wall. It is definitely worth more, but this is what I can afford at the time. I imagine that bidding would go higher.

Oh, and you could contact this guy...
http://kotaku.com/5908177/can-you-na...-on-my-forearm

I'm sure you could get an article about the auction on Kotaku.