If you want the HTC 10, then you should purchase it directly from HTC, as that provides you with the free Uh-Oh protection for one year. If you purchase it from another retailer during this time period, HTC is offering buyers $100 in credit to use on accessories -- excluding Vive accessories -- at HTC.com.
When we see large price cuts like this just three months after release, it's usually indicative of poor sales. You can sometimes find US carrier sales on the competing Samsung S7 and S7 Edge, but four months after their release, these devices are mostly still being sold at their full $680 and $790 prices.
The HTC 10 is a fantastic smartphone that is extremely well built, super responsive, takes great photos, and powers through a full day. However, the OnePlus 3 has a similar all-metal build, front fingerprint scanner, and high-end specifications while being priced at just $399. With the $100 discount, the HTC 10 is still $200 more than the OnePlus 3, and I have a hard time justifying why you should pay this premium over the OnePlus 3.
While I own a dark gray HTC 10, my T-Mobile SIM keeps finding its way into the Huawei P9 because I enjoy holding it in my hand and taking black and white photos with the dual cameras. There are so many great Android smartphones from Chinese manufacturers like Huawei, ZTE, OnePlus, Motorola (Lenovo), and Xiaomi that it is tough to justify paying $200, $400, or $600 more for a smartphone from Apple, HTC, LG, or Samsung.
ZDNet's Jason Perlow presented the Game of Smartphones, and it seems that the Chinese brands might be having a direct impact on pricing for the major players. While the Apple iPhone is made in China, Apple has a massive premium on its phones compared to the likes of Huawei and OnePlus.
While HTC is offering $100 off the HTC 10 in July, I think we could see this offer continue as HTC tries to stay in the competitive smartphone game. It's a shame HTC didn't release the HTC 10 a couple of years ago. It might be too late for the company despite having a winning device in the HTC 10.
Related ZDNet HTC 10 coverage