I am hoping that was meant as a joke?
It’s the buyer taking all the risk and not you as the seller, the think is, nobody has approached you to sell the account, you are looking for people to buy. This will always put you on the back foot.
Any kind of guarantee either way in my eyes would be worthless anyway, and therfore pointless. What’s the chances of you paying back 5k if the account takes a drop in revenue? and vice versa?
I’m sure someone will buy the account but for nowhere near the amount your looking for. The more information you can provide the better, get all your stats for the past 12 to 24 months if you have them.
As with everything nowadays it’s a buyers market, could you not just keep a hold of the account? after all it could be 6k a year for life.