Here are some links to eBay payment methods and policies:
http://pages.ebay.com/help/policies/accepted-payments-policy.html
http://pages.ebay.com/help/pay/methods.html

Yes, checks and money orders are good for sellers -- there are no PayPal fees.
Unless they are hiding income or some other reason, I can't see why buyers would use anything other than credit cards to buy stuff (via PayPal or some other approach). Credit cards are the buyer's best friend, or rather the threat of a charge back is the buyer's best friend. Your credit card number can not be seen by the seller if you use it with PayPal. You can't be stuck with unauthorized uses of your card. ... ..... For example, if you are haggling with a seller over the condition of the item you were sent and want a partial refund if you keep it or a full refund if you return it, you are more likely to win your argument if you paid by a credit card...... ...... I once posted this;

PayPal is the best thing in the world for buyers. Tie your PayPal account to your credit card, only. Drop the link to your bank account. Make all PayPal purchase/auction payments via your credit card through PayPal. That puts you in a very powerful position. If something goes wrong, you have the threat of a charge-back as a powerful weapon. And if worse comes to worse, you can order a charge-back. In effect, only pay for things with your credit card.

Robert