I've purchased lots of stuff on E-bay from European vendors with international wire transfers using swift codes. It's secure, albeit expensive. There are wire fees, (typically 25 to 35 dollars), on both ends of the transfer. I suppose there's always the risk the vendor won't mail the purchased object after receiving your wire transfer, but this has never happened to me. And in the end, there's the same risk with Paypal also, (although in theory, Paypal may be of some help in getting your money back).
Ask the German vendor if he accepts Paypal. Point out to him that it's much cheaper than an international wire transfer.
Elton