There is no direct rule stating the 1st one gets the prize. But Honor and your word are what we operate on in here. If you agree on a price, set up a FTF then honor it. Pretty simple. Do not hold out for a better offer. No auction like activity's.
I have dealt with a couple of carrot hangers in the past. It is not cool.
I have dealt with a couple of carrot hangers in the past. It is not cool.