It’s strange that while 4K resolution rapidly became ubiquitous in televisions, showing up even in the cheapest Walmart TVs stacked by the door, it’s still considered a premium feature for computer monitors. Well if you’ve been looking for a 4K upgrade on the cheap, Acer has your back. Today Amazon is listing a 28-inch 4K monitor for just $199.99. That’s $300 off Acer’s MSRP…but more accurately, $100 off Amazon’s regular price. While it’s a little smaller than some 4K monitors, this display ticks all the check marks for a seriously useful office display. In addition to the 3840×2160 resolution…