We use a new Makerbot replicator 2 for basic 3D printing, yes the finish is not ready for painting but for some parts this can be satisfactory, with 3D CAD CAM it's also worth considering 3D routing and milling. This can produce a superb finish but with limitations due to the cutters involved and on basic machines no undercut - some come with a rotary 4th axis though and this really increases the scope. Finally don't forget laser cutting and engraving, it's more flexible than you might think.
Replicator about £2500 but cheap materials at about £20 a roll - lots of colours available and now some new flexible rubber-like materials as well. Our new CNC router/mill which will work on most plastics, woods and non-ferrous metals was about £12,000 including extraction. A good laser cutter starts around £10,000 and goes up, we have a 60WATT approx. A0 machine which cuts woods and acrylic superbly well.
I keep saying we, it's a school and it may be worth approaching a local secondary/high school to see if they can help - we’re all trying to make ends meet these days and we have done several jobs for people at very little over cost price.
Clive