Wow.. what an amazing Pokemon gamertag. I happen to love that pokemon and Its very recognizable too. I really don't know the Pokemon Gamertag market to well, but Ive seen a 1st and 2nd Gen sell for $30-40.00 each.
To a die hard Pokemon fan I think it would sell for a little more though.
GLWS!
EDIT: Now that I think about it, I saw a 1st Gen sell for 80-120$ a couple months ago. It all just depends on who is interested in buying it.