My seller wasn't listed as international either, however, she gladly agreed to ship the unit internationally after i asked. Never hurts to try & ask...
Also, you get more hits (some times) when you tick Location: Worldwide under Options. And try searching for Sony Reader instead of PRS-500 (you'll get about 8 pages of card readers and similar equipment, but you'll also get a few more right hits).
Just BTW, got mine for the store price ($350)