This sorta sounds like my mother, when ever something was happening that would cost alot of money she would always ask if so and so would work like said or every time on things that could slip up( Or, like " Are you SURE you'll pass that test?). This might just be a noob worried about it that is trying to feel reassured about his "Large"("" because im not sure what most people consider large or not) buy will pay off sooner rather than later. I cant see how they would scam you after sending you money and you shipping the snakes without it being easy to get the money back if its through paypal, though I could be wrong. This is just my thoughts about it, and you being the selling, if you do not feel comfortable selling to this guy by all means do not. Just tell what the genetics are and each egg has one and four shot of being a pied.