That's my point though. People charge that amount for an infernal cape itself, but when it comes to accounts they offer a lot less. It's the same concept with accounts that have 83 construction. You could build a pure with decent stats and 83 con, and it's highly likely that people would value it at less than the price of 83 cons. Sorry for the rant, it's been occupying my thoughts for a little while now and this was the perfect opportunity to clear my mind.
You might be able to get a lot more if you can find the right buyer, but I can't imagine it being in the bills. It's a really nice account though, infernal on an augury tank with penance pet. You have my kudos.