I bough a coloured lazer jet, and do all mine in house, design as well. I just found using these services are too expensive in comparison, and I need to do a certain amount of printing at home for invoices, reciepts, letters ect anyway.
What I dont like is if you have a little colour logo at the top they charge you the price of a full coloured page, but just black and white doesn't look as professional.
So I go with inhouse.
Its a HP Colour lazer jet I use, £150 from misco, still not changed a catridge since I got it about four/five months ago. Done loads of double sided brochures and letters. Since the ink is only about 1 1/4 used it should last me all year and then some, but I guess it depends on how much printing you actually do.
Hope that helps
gerard