Paypal is pretty easy. I use it all the time, a bit too often to be honest.
Create an account, fill in your credit card info or bank account.
You only need to login and fill in the sellers e-mailaddress to make the payment.
For large payments for goods, you cannot use gift obviously (although I got away with a lot of them). So make sure to add 5% to the amount asked by the seller.
But I would always mail the seller about that first.
That should do it I think.
