Paypal won't help you much if you deal with a bad seller. Happened to me once. I bought a lot of items from an ebay seller. The items has less quality that they were advertised for. Went to Paypal (since I paid with Paypal), and asked to dispute charges. To make long story short, I lost both the items and my money.
Postal Money Order might be better. They have certain procedure to track the MO.