Is that price really supposed to be 0.75BTC or is that a typo?
I don't really know the prices of accounts here but i know they are not what they used to be.
Is the account enrolled in any signature campaign or sold with original private key for the address you will sign?
Yes, it's 0.75
BTC, but you can pm your offer

.
It's not enroll on any campaign at the moment. But i won't sold it with the bitcoin address to prevent any future dispute.
But wouldn't that mean in future you could come along and say the account had been hacked and that you are the "rightful" owner - indeed if you have changed the password a couple of times you could also say that you were on vacation and didn't know until you got back.