What will bring 4k to the masses is likely to be next generation gaming consoles. The suported resulution is ofcourse one thing and the actual used is another. Expensive graphic cards will drive up the price of the unit. Lover price usally results in more sales. Still there was a few(inimportant) titles on ps3 and 360 that had true 1080p resulution.

High qality pc monitors over 1080p has been pretty affordible. 2560*1440 is usally more affordible than 2560*1600. I wouln't call $500 for a monitor expensive.