Considering the capabilities of the 3DS I'd still say you should buy it even if you didn't have money leftover for any games.
The resolution isn't as good as the PSP's but it's pretty close. The analog stick is way better. I do believe that the 3D function is bad for your eyes. I'll have to do some research on that. Anyway, with 3D on, the resolution is 800x240 (Or something close to that. 400 for each eye really, because of the split imagery.) and without 3D it's something like 400x240. By comparison, the resolution of the PSP3000 is 480 x 272.
The game cards are 2G, as opposed to the old game cards ranging from 64M to .5G (or 4Gb). The system itself is powerful enough to run the same engine that powered Resident Evil 5 and Lost Planet 2.