My favorite 4K display is on an excellent sale price today at Amazon; the LG UD2768P-B, the brightest and best specs of all the LG 4K displays in this series, is only $369 today (free shipping). This model has super slim bezels, ideal for multiple display setups (I have three side-by-side; several people in our group also have three or two; I favor this model highly over the Dell using the same panel from LG).
LG Electronics 27UD68P-B 27" Screen LED-Lit Monitor https://www.amazon.com/dp/B01F3H4JGK/ref=cm_sw_r_cp_api_i_jD5iCbHYWX6H9
(I get no commissions from this link; I don’t even know if it’s appropriate to post this kind of thing on this forum; @ace Adam, I won’t be offended if you delete this post.)