I almost always pass over any auctions that do not accept paypal. Especially if they require Money Order or Cashier's check. It is just not worth my personal time, gas money, and bank fees to run out to the store or bank and purchase a money order or cashier's check.

I've used paypal for almost all of my ebay purchases and never have had a problem whatsoever.

I would love to be able to pay for non-ebay transactions with Paypal as well.