Grab this Samsung 28-inch QLED 4K monitor with FreeSync support for $330
http://www.pcgamer.com/grab-this-samsung-28-inch-qled-4k-monitor-with-freesync-support-for-330/
Over at BuyDig, you can snag a Samsung 28-inch monitor (UH750) with a 4K resolution and FreeSync support for $330 with free shipping. Just apply promo code BCD71071 at checkout, otherwise it costs $448.
That's the lowest price around for this display—Samsung has it listed for $500 on its website, and Amazon has it on sale for $394. To find a better deal, you have to either take your chances on Ebay or with a used model, the latter of which can be found on B&H Photo for $265.