(*with VERY rare exceptions)
Paypal is convenient, secure, and it gives me a third-party record of the charges to my account and the payment made. It also gives me the option to take back a payment that isn't claimed by the seller, or to reverse a transaction if there's an error. I can pay instantly, get a record that the payment was sent, and often the item gets shipped within a day or two of the auction close. I generally receive the items I bid on within a week of auction-close -- the record is 3 days, and that was a Texas to Michigan shipment by regular US mail. I've used them for about 100 transactions, and I've NEVER had a problem.
Also, once upon a time I upgraded my account so I could get a payment from a friend's credit card, and since then I have received payments once or twice that were from bank accounts and DIDN'T get charged a fee. Maybe it's because I don't RECEIVE very many payments, but I thought you only got charged if the money came from a credit card?