So.. I was very happy and considered myself lucky winning an auction of a Pokemon Platinum game for just 17 GBP... the packaging was ruined by mail, but the actual gamecart was extra wrapped and survived it. Booted the game, that worked too. So I gave the dude good feedback.

But then I tried playing it.. and the game gets stuck right after you get to choose your name and rival's name and stuff, so when the actual playing begins..

Contacted the seller, I really hope he plan on scamming me, because if he was, he scammed the wrong person.

Edit
The guy refunded me completely and appologized, he didn't know the game was defect.
Time to hunt down a new game..