I had a similar thing happen that I did take the time to follow up, I no longer have the e-mails but I’ll give you the gist. I was selling my iPhone on gumtree (cos they are shit :P) and I got contacted by a nigerian who seemed interested in buying it. He said we should use a 3rd party company as we would both be protect that way.
I took the time (since he already knew the e-mail address was valid) to write back with a sarcastic e-mail explaining that I knew he was scammer and that I hoped that he was happy trying to make a living this way.
He wrote back saying that he was in fact a legit person and only wanted to give me more than I was asking for the phone. I promptly told him to piss off and that no-one would ever believe him. He then sent me a 3 page hateful e-mail, entirely in caps, explaing how I was infact a scammer in the most broken english I’ve ever read. It was pretty funny I wish I’d kept it. I simply replied that I hope he enjoys his shit country and that he dies young, a balanced and measuured response.
Pretty funny though.