Yeah I've sent heaps of stuff to Portland that's been bought by seemingly-foreign accounts like this.
Internationals use Oregon in general as a shipment hub (like we use SMC Oregon) because there's no sales tax, or tax they usually pay when sending to Europe etc. I wouldn't be sketched out by this in itself, but I would be looking up the address and the buyer's feedback record.
Automatic payment is great since it stops people making offers that you accept, and then they never end up paying for