Of course it's more expensive. Dealer want to win no matter what! Just sit tight until you get a definitive response from the owner, which, after a few excuses, will probably be mid-next week.
I think 2 opportunities to fix the bike is all I would give them. Let them have this attempt at fixing it, say you want to be shown exactly which gaskets they've replaced/resealed and if at the end of that it's not fixed you want your money back. I wouldn't swap or buy anything else off them personally, these dealers never lose much in these situations. Even if they gave you a straight swap on the gsxr all you'll be doing is reducing their profit margin on the suzuki slightly. You take your money back and you're hitting them where it hurts, which is exactly what poor service deserves.
Also, make sure you confirm that you have a fresh warranty on the work they carry out. If it starts leaking again in 6 months you don't want them to turn round and say you're out of warranty from your original purchase date.
