They need to stay up.
They dont spend that kind of money on first team players generally, let alone players they arent going to play.
Plus i dont think Delap would agree to a deal like that either - and generally lying to a prospective new signing isnt normally the done thing, it wouldnt work out well.
Buyback clause is basically a bit of a win-win for both teams. No, they wont get a world record transfer fee for him, but if he does superbly they have had his goals and gained some money. Its better than loaning a player for a year and losing them at the end like they did with Broja last year.