I know I’m juvenile but I love this item on eBay (it might be fake or this is just a mirror of it): I will kick you ass:
Winning bid receives an ass-kicking from me personally. I am 6’0″ and weigh over 230 lbs. If you win this auction, I will personally come to your house and kick your ass. I guarantee that I will not break any bones or kill you, nor will I use any weapons on you, but I will give you a good beating. I will do this under two conditions:
1) You or anyone else does not press charges against me(after all, you bought the ass-kicking),
2) You do not fight back or attempt to physically harm me in any other manner (this is your ass getting kicked, not mine).
Buyer provides round-trip plane ticket to the nearest airport, as well as cab fare to your house and back. Do not pick me up, as I will be attacking you completely randomly. Most likely though I will just fly in, kick your ass, and then leave.
If you are married or have children, I may choose to slap around your family a little bit, but only if I’m feeling particularly generous. They should be informed of this, and expect it as well.