Ever since the 4K consumer resolution first hit the scene, one of the biggest hurdles in adoption has been price. Well, as with most things tech, things have dramatically improved over time, and I think it's safe to say that we've reached a point where a lack of adoption right now has little to do with price. AOC's U2870VQE is a good example of why.
The U2870VQE, for starters, is a 28-inch screen - so it's hardly teeny tiny. Yet, despite that, and the fact that it boasts a 3840x2160 resolution, it's currently available on sale for $349 at Microcenter (SRP is $499; Amazon currently has it for $466). Of course, there are a few caveats, but even so - 4K... 28-inch... $349. That's amazing.
The biggest caveat is the fact that the monitor uses a TN panel, but that's something no one should be surprised by. In time, I am sure we will see IPS 4K panels this cheap, but even some high-end gaming monitors today still use TN, due to their sheer speed. Tying into that, the U2870VQE is great for gaming, with its 1ms response time. Its 300cd/m2 luminance doesn't make this the brightest monitor on the block, but it's still likely to suit most people just fine.
It's important to note that this current $349 is not necessarily going to stick around for too long. While AOC tells us the monitor's SRP is $499, its regular price at Microcenter is actually listed at $399. So even if you miss out on the sale price, the regular one isn't too much worse. Still - if you want a big 4K monitor on the cheap, the U2870VQE looks like the best route to take.