is really worth, not from some opinion that your friends might have, , etc.
if you want to make a sound decision, you need to know the realy market price for your house. b/c all the calculation is base on the extra $300,000 you couuld get if you back out.
If you can not get $300,000 after backing out, you are losing the penalty fees you might have to pay the current buyers, the vancacy cost of the house, extra attorney fees, etc.