The Samsung U28D590D 28-inch Ultra brings 4K to the table (or your desk) at an affordable price. As screen technology goes, you do not get an IPS display for this money, but you do get a very colour accurate TN panel with a 60Hz refresh rate (when using the mDP connection). Older generation 4K displays only offered 30Hz which was fine for movie watching, but not that great for business/work use and abysmal for gaming.
You can pick up the Samsung U28D590D here in the UK, or here in the USA (pre-order in the UK with a 1st May 2014 release date, in stock in the USA).