Be aware they will all be grey market and you will not have a warranty. The sellers act as only as middlemen. So you will be on your own if there are any unbalance problems in the earspeakers you recieve.
That said, I have had very good experiences buying several Stax from PriceJapan.
They will be grey market as far as Stax may be concerned, but unless anything changed PriceJapan is including a one year warranty policy. You are as much on your own or not as with any other retailers (based on the reputation and business continuity of that retailer). Nowhere overseas a buyer deals directly with Stax afaik. In some countries in Europe an extended warranty is offered by some dealers, for the (much higher) purchase price. It's up to anyone to decide what's better value for them.