I was able to get one recently from one of their authorized resellers, albeit at a bit of a premium.

There are quite a few on ebay if you're desperate for one. Probably won't find the newer 4-NIC models, though.

Ebay or a licensed reseller (if there are any) should be easier anyways. I remember them requiring a VAT ID for EU customers. I ordered a couple for a small business so that was no problem back then but private individuals are pretty much out of luck.