We we're looking at purchasing our own unit in house before the market and project load tanked. Personally I've been waiting for the mcor matrix 3D printer to get released.
We push to do everything as green as possible, which most 3D printers aren't. However this one uses paper and glue to build the models, so your waste which is just paper is completely recyclable. Not to mention the stock is as cheap as paper.
http://www.mcortechnologies.com/index.html
If you do take this up as a printing service, the sustainability benefit could be a nice selling point on your brochure.