That got my Wheeler Dealer radar up. Went to check NADA on what it is worth...
Clean Trade - $37,475
Clean Retail - $41,225
My rule of thumb when selling as a private party is the selling sweet spot is 1/2 between clean trade & retail. That would be $39,350. So yes, his price is good but surprisingly isn't outrageously good. The deal is most likely legit and he should be able to get it sold for that price. I just wouldn't be able to buy it and make any money on it.
Cayman prices in general and base models in particular have really dropped in the last 4-5 mo. And I don't think it's all just seasonal.