Sounds like the perfect time to buy a refurbished HTC One M8.
Unless the M9's 20MP camera is a must-have, the M8 can serve you fine. And instead of spending over half a grand on the device, you can pick one up for $289.99. You even get your choice of gray, silver, and gold.
There's always the risk of the device coming with some minor cosmetic damage, but everything should arrive in working order.
Shipping is free, but while the seller is willing to ship internationally, many parts of the world are excluded. You're fine if you live in North America (except Mexico), most of Europe, and in Australia. The item is not available in Africa, Asia, South America, and a number of scattered countries. Try your luck just to be sure.
As for sales tax, that's only in California.