Judy, that's a good question. Nowadays, it's so easy to get a debit card, even those prepaid ones, why not use that instead of sending cash.
Thinking from the buyers side here: what if the seller receives it but said they didn't? Not suggesting OP would do this, but you never know. I always stress for the security of my buyers, I would prefer paypal or DC. At least they are somewhat protected. If they pay cash, they are putting an enormous risk out there.