There may be slight technical differences, but I cannot say that I have noticed any visual difference anytime I have had to use that set up. It acts exactly like another VGA port.
Also, that somwhere down the road may be closer than you think, there are some good deals out there:
Newegg.com - Acer G215HAbd-1 Black 21.5" 5ms Widescreen LCD Monitor 300 cd/m2 ACM 50,000:1
Newegg.com - ViewSonic VA2431WM Glossy Black 23.6" 5ms Widescreen Full HD 1080P LCD Monitor Built-in Speakers 300 cd/m2 DC 100,000:1(1000:1) Built-in Speakers
I personally use a ViewSonic similar to the second link.
Generally modern monitors can be connected via VGA or DVI or HDMI, because of the limitations of the VGA (non-digital) spec I would not recommend it for connecting high resolution displays. However DVI and HDMI are basically the same, I have seen HDMI described as "DVI + Audio + ridiculous markup".
Also, that somwhere down the road may be closer than you think, there are some good deals out there:
Newegg.com - Acer G215HAbd-1 Black 21.5" 5ms Widescreen LCD Monitor 300 cd/m2 ACM 50,000:1
Newegg.com - ViewSonic VA2431WM Glossy Black 23.6" 5ms Widescreen Full HD 1080P LCD Monitor Built-in Speakers 300 cd/m2 DC 100,000:1(1000:1) Built-in Speakers
I personally use a ViewSonic similar to the second link.