You can hack a PSP fat regardless now, but before that Lumines was a hot commodity, people paid $50 for it, maybe people still do
A PSP Slim comes with a 1GB and a movie and a game, and more features and such, and I think it's $180 out of the box, so you're gonna have to sweeten the deal with the 12 games and your trinkets.
Mention what firmware version it is, people who want to hack their fatties want to know. Be sure to mention this in conjunction with Lumines. Simply say you weren't interested in homebrew, but for those who are willing and have the know-how, they have access to it. PSP Homebrew is a system seller, so I'm repeating myself here but try to hammer this home.
I'd say try and pawn it all off for $250 (still a killer amount for what you get) to 275, 235 if you really want to play it safe
You can beef it up with over-charging for Shipping, but I'm sure they won't notice... teehee