"Your money" means they had responsibility for it. It wasn't somebody else's money they were lying about. Peter does not point out the lie as the only sin, incidentally, only as the sin which brought about their death.
All discussion is pointless, when words lose their meaning. "Your money" means it belongs to you. You have the power to decide what to do with it. The commandment not even to want the other guy's stuff, which is what coveting is, came straight from the Highest authority.