COD CAN be your best friend IF you pay with a personal check. If the guy send you a box full of bubble wrap, and you hand the mailman a money order, you're cooked. A check can be canceled if you open the box and find it's a scam.

I was promised about $500 worth of gear, handed the postman a MO and sent him on his way. I opened the box, found a broken, leaking, barreless spyder, a VL200 hopper and a 12oz CO2! Lucky for me, the postman makes frequent stops. I ran him down, swapped him a check, canceled my check, and then demanded the seller give me $20 to cover the cost of the check canceling. He refused. I told him to kiss his gear goodbye. I sold it for $30. Luckily, it all worked out, but FYI, COD can go wrong.