Also how often will you be printing?
Are the models for you or for clients?
Do you want models (there are services of that ), Or are you actually interested in doing the printing your self?
I know I want a 3d printer, but that is because I am a tinkerer, however I do think some people would be better served by a printer service, so I want to be fair with you about what you would be getting into.
Owning a printer:
In the long run you will get you prints faster
You can iterate much faster than using a service
If you buy a cheap printer your cost per print will be lower in the long run.
3D printing is not currently at a click print and go walk away, there are a lot of settings that need to be tuned for your specific printer.
3D printing requires a lot of DIY mentality, this could slow you down
Prints will have layer lines in them
Prints often fail.
one or 2 color printing
Support material is currently a lot of work to remove
Using a print service (shapeways, Imaterialize, ETC)
Full color printing is possible
Extremely high quality prints
Can print in many different types of materials
They decide if your object is really printable
Support material is pretty standard
You will wait about 2 weeks to get a print back
Prints prices are pretty high, Expect $50+ (for what you are getting it is reasonable)
Iteration takes a couple of weeks to get the prints back
Honestly, if I was an architect that wanted to print 10-50 models, I would include the print cost in my quote, (you can get a feel for how much it will cost based upon the size of the print in cm^2), and I would use a print service, You can get full color prints meaning it save you a lot of time in painting and finishing. If you wanted a full color printer it will be very expensive to buy, and the operating costs are pretty high as well. The other benefit of print services is that they check over your models before printing, that means that you are less likely to get back garbage. I have used shapeways in the past I thought they did a great job. After using them I did a lot of looking, and now I have purchased my first printer.