Posted By:
EricI could cover most of NJ.
Regarding your question: I would ask for references (i.e. Ebay ID, people on the board that he's dealt with and then contact them to see how the deal went). If you feel comfortable, send the card by USPS registered mail. It's the safest way to ship anything of value.
If he hasn't dealt with anyone on the board, I agree with the previous posts. Find a middleman that both of you could send the card to, and have that person send each of you your new cards.