Can I trust buying a Bengal Kitten from this guy?

I don't think you should if you haven't seen this cat yet. What if he's ill-tempered? Or the kitten is something like three-legged? You don't want to pay so much for a cat if it's not what you're looking for. You should go to an adoption center to get a cat. It costs way less, and you're saving one less animal from getting "put to sleep". The adoption center's cats are all sweet and healthy just like any store's, but they need a loving owner. Anyway, good luck :)