I have a 32" QHD monitor (2560x1440, or 4 times the resolution of a 720p TV; cost way more than $50) replacing a 24" HD monitor that burned out after ~10 years. My NVidia GTX 970 monitor can handle it, but it's at the upper end of its range. All the text seems about the same size (the increased resolution was matched by the increase in surface area), so I am not complaining.
I would be concerned, however, about placing 4K video content onto a smaller screen. Please let us know how it works out and which graphics card you are using to drive it.
TC Pro Platinum 2017, 2016 & 2015 (all with LightWorks) & V21
System: i7-5820K @ 3.30GHz, ASRock X99 Extreme4, 16GB DDR4-2133 RAM, Gigabyte GTX 970, Samsung NVMe SSD 950 (256GB), Windows 7 Pro (64-bit) SP1