Yeah you should be able to add a maintenance contract for a used one ok. I imagine your sales rep could find you a few used ones going for a decent price too - just make sure you push them on the price a bit, don't ever accept their first offer! Given the current economic climate though, there's some stonking deals around.
Card per page? Not sure what you mean, if you're talking how many up (I'm based in UK so use SRA3) it's either 21 or 24. You can expect from 7-15p per page for a click charge. I've heard it works out about 50p per page if you buy the consumables yourself!
If you get a half decent tech and operator the FTB registration works out about 1mm. The one I run at the min is bang on for three corners and 1mm off on one (talking crop marks across the whole sheet - the image isn't exactly square - common issue but hasn't caused me any problems, even when sending jobs for die-cutting).
Make sure you run Xerox stocks (it's worth it in the long run) or at the very least something specifically made for digital.
I like the 240, it is a nice printer to run once you know what to watch out for and when to call the techs. It is certainly plenty of machine to get you started doing business cards - that's what I mainly print on mine.
