This really sucks. My second-ever pin purchase was a TZ (which at the time was supposed to be my one-and-only pin... oops). I had sent a several-hundred dollar deposit to a seller who held it for me a few days, and I was driving up 2 or 3 hours to pick it up.
The night before I leave, he sends me a message that he's backing out. I was *furious*. I (forgetting that not everyone has integrity) thought we had an ironclad deal, due to the deposit. Not so, apparently. "Oh yeah I decided to keep it." Uh, ok.
I sent him a couple of nasty emails and explained I had already spent a bunch of cash getting the truck and gas as I had driven home early from a trip, etc etc. He offered to reimburse me for the gas, which I thought was the least he could do, and this calmed me down. Cooler heads prevailed, he refunded the deposit, I continue looking.
then 2 months or so later I see the EXACT same game for sale on Pinside, jacked WAY up in price. All class.
So yeah I feel ya - I feel like I have an obligation to sell even if I've just verbally agreed; extenuating circumstances, sure. But in my life and in my business, my word is bond. I've screwed that up a number of times, but that's always my goal.. Not everybody has the same viewpoint on keeping their name on the up and up, unfortunately.