Is it wrong to win a 10$ ITunes giftcard in a 5$ charity competition?

The other day I played in a ga-ga tournament (no relation to Lady Gaga) and I came in first place, with my prize as a 10$ ITunes giftcard. For some reason that just doesn't seem quite right to me. :P
Whacha all think?

(Here's a video showing people ga-ga)
http://www.youtube.com/watch?v=sO73MVAkhzw
I would like to note that this match is severely unfair as the one guy is really good and he is playing with all girls. (Not that girls aren't good at ga-ga, some are spectacular.)