I'll post a very short sum-up:
I offered $150 via PM. Seller demanded $300. I agreed and posted it in the thread. I noticed that he also holds the trademark GAMBLY. I asked and he offered to either sell both together as package for $750 by bitcoin or $1,000 by Escrow. I demanded a contract then and collected some proofs. We added more things which I demanded to the contract over a period of 2 days.
Then I decided to pay $1,000 instead for security reasons and asked him to change everything to Escrow. He accepted and created an Escrow transaction. I couldn't pay this one because it was the equivalent in GBP and no credit card was therefore accepted by Escrow. He then offered to pay him €945 by Undeveloped. I checked his profile there and tried to pay. My card payment was declined.
Then I finally made the decision to pay $750 by Bitcoin. Firstly, because we spent 2 days for the contract. Secondly, because he had an escrow and undeveloped account, I could clearly track down his domain, email and other profiles, company, business activity of the past, trademark, etc. Plus he tried to get my Escrow and Undeveloped payments. So no reason to still be suspicious with all this. Well, boy was a I wrong. Obviously, some people scam out of emotion, just when they see the opportunity.
He said he didn't receive the payment, quickly deleted our signed contract from the cloud (which I saved before but he didn't know) and transferred the BTC amount away to another BTC address 40 minutes later.
In the morning, he replied from the same email address that was used for Escrow that he wouldn't have any Escrow or NamePros account and threatened me. Since that he keeps writing untrue things despite the fact that I can prove every single detail. The newest story is that the BTC reached his account but he was somehow scammed and they aren't there anymore. Also, he deactivated his LinkedIn, and he added more privacy to his Facebook account. Now you can't see his friends anymore, for instance. But I saved everything before he deleted things.
I've offered him to solve it. Else denounce and more to come. So the conclusion of the story is that people can still scam you even when they first didn't have the intention (escrow, etc) and if you have full evidence. Some people simply don't care about anything.
The BTC address and many other legal things are part of the signed contract. You can find the transaction here and see how he quickly transferred it away like a little scammer.
https://www.blockchain.com/btc/address/1FLMbrF9RRvWZApLZQ2UmQ37v7DsBfBtsR
@Oliver Maggs, if you want to solve this in a better way for both of us, for you too, then you know how to contact me.
IMPORTANT: If everyone who made a payment to this user can please contact me, no matter if they get a refund or not, I would be thankful. Then we can take actions together.