Costco has the Acer CB342CK 34-inch IPS FreeSync monitor down to just $349.99. That's $50 off Costco's regular price, and this deal comes with free shipping. The page says the deal expires Dec. 26, but it's more likely to disappear long before that. You will probably need to be a Costco member to avoid paying a surcharge.
Visual Response Boost
The specifications on this monitor include a 3440 x 1440 pixel resolution, a 75Hz refresh rate, and a 1ms response time when using Acer's Visual Response Boost. It's also HDR ready and has AMD's FreeSync technology.
$400.00 $50 off
The monitor has a pixel resolution of 3440 x 1440, a refresh rate of 75Hz, and a response time of 1ms. The refresh rate isn't the best of the best, but it's a lot better than the default for most monitors, and it'll look great whether you're using this at the office or for games at home.
Since this is an IPS panel, it probably has a native response time closer to around 4 to 6ms, but Acer has a special technology called Visual Response Boost that helps it reach 1ms. This tech inserts a black frame where appropriate to help reduce motion blur and keep response times low. The trade off is the black frames significantly lower the brightness of the screen. Of course with IPS panels you also preserve the 178-degree wide viewing angles and supreme color accuracy compared to other panel types.
Although the monitor does say it's HDR ready, you're not really going to see a lot of great HDR support with this display since its native brightness is 250 nits and the VRB brings that down more. You really need a minimum of 400 nits for good HDR, but that's really the only negative about the display.
Reduce screen tearing with AMD's FreeSync tech. The monitor also has two 3W speakers. Connectivity options include two HDMI ports, one DisplayPort, and a USB hub with 4 USB 3.0 ports. It is also VESA mountable with the 100 x 100mm standard.