Scam if ever I saw one. However instead of pointing This out as soon as possible to your "buyer" why not have some fun with them? I had a few offers like this when selling a previous car. I promised the money so so many times to them, tried to sound as gullible as they come and arranged many many times to pick the agent up from the airport, the the train station. Then eventually my local town. Except it wasn't. After being questioned, I suggested to the "buyer" that Glasgow was virtually right next door to Edinburgh and he might as well get the train there. I (obviously) never turned up once, and neither did he/she. In the end he got so furious I was dilly-dallying about, it was hilarious. Neither of us meant to keep any of our promises and nobody got hurt.
A massive waste of time tho, I had time to kill back then.
Definite scam tho, I'll see if I can recall any old emails and compare notes with you.