These two statements contradict each other. I am very confused by your escrow system now. Are you holding the coins when you make the quote or are you asking the seller to send the coins to escrow after the deposit is confirmed? I am not trying to smear your service I have used it many times and have never had a problem. I am simply trying to understand the system.
Sounds like both are true.
1) BB holds the coins in escrow.
2) Depositor buys coins.
3) BB askes seller for new coins to replenish escrow.
and repeat...