I have a late-2010 Macbook Air with the nVidia 320M, which can handle 2560x1440 over the mini-DP. I have the Acer B326HUL which was $399 on Black Friday. Seemed like a good compromise since driving 4K would mean a new laptop.

Compared to the 28" 1920x1200 monitor it replaced, I'm very pleased with the 32" 1440p.