As for payment, if the vendor is unknown, this can be tricky, as if you pay by bank transfer, you have to rely on the honesty of the vendor, and there are scams going on where people see what is sold on ebay, contact the second highest bidder, convince him they are the vendor and the highest bidder did not complete on the sale, and they are offering it to them as the second highest bidder.
Exactly that happened to me on a Europa sold in the USA. The contacter was a scammer and had no access to the car, and was not connected to the vendor. Luckily I smelt a rat before parting with cash.
In this case the vendor is well known, so payment by bank transfer is the easiest way.
You need the vendor's account name and account number, the name and address of the bank, and the iBan or Swift Code.
Your bank will charge you £25 for the privilege of doing this, and the exchange rate should be close to £1.00 = $1.60.