If you already did much negotiation on the price and feel it's the best you will ever get from anyone, then it may be easiest to go with $15K like before.
However, if the domain is of a highly generic nature and/or you have received other decent offers in the past, even if much lower, then holding out may be worthwhile and profitable, though certainly there are no guarantees.
Going higher may come across badly to some buyers, but this is business ... if they really wanted it at $15K, then they shouldn't have "canceled" the purchase. Something is worth what another is willing to pay - if they come back to you after they've already "canceled", they're likely willing to pay $15K and then some ... whatever amount, within reason, just to get the deal done
Speaking of escrow - escrow.com only handles the financial side of the transaction, but that's where most problems happen. For extra security, Moniker is excellent ... but will add time and complexicity - if you're relatively certain you're dealing with a bonafide buyer who has real assets, escrow.com is likely sufficiently safe enough.
Ron
