Whoa....
What's the old expression; Money Talks and BS Walks?
I have had at least as many committments to buy our tailight kits as I have had actual sales, and we've sold many dozen. My conversion rate of those committing to buy via email or forum post, who actually end up buying, is less than 30% - that means 2 out of 3 committing to buy don't. My accountant (me) and the IRS would go bananas if I counted every email committment as a sale, and they'd be right. Fact is, most of my customers are unknown to me before their checkout on the site and simply go to the site and buy, not feeling the need to inform me that they're going to beforehand.
Maybe the guy got hit by a Bus, maybe his wife found out, maybe he lost his job and is so low that he cannot bear contacting you to retract his committment. Fact is, none of that matters - It ain't a sale unless the money's in the bank.
If you want to count your chickens before they're hatched, seems to me the problem isn't with the supposed buyer.
If you have to purchase materials to produce it, require a non-refundable deposit equal to your material costs. Even that's no absolute assurance, but at least you're not out-of-pocket. Esty, you and I once discussed a carpet kit, but in further discussion with you, I found that I needed to finish my 5-spd. conversion in order to get the correct carpet (good thing I did because I'm going to go another way). When I am ready for my kit, I'll contact you and send paypal within 30 min. of your reply.
If an amateur seller, simple solution; don't accept 1st dibs, but 1st Paypal notification. List your parts with the statement that the first one sending Paypal wins.
Committed buyers are not going to have a problem with this, their intention is to buy.
I think it's pretty 1984 to start publishing lists of whom you percieve as committed buyers who never followed through. There is no buyer until the money changes hands. Anything else is something you agreed to accept and therefore cannot b*tch after the fact because it fell through.
It's unfortunate, it p*sses you off, but it's also reality...especially in today's economy. This is a case of Caveat Venditor
Cheers!