If you do not need color, get an HP 9000 or 9050 LaserJet.
This printer is about 50 pages per minute, BUT
pound for pound, it runs and runs.
I have a 9000 in the field with about 5 million pages on it. It shows no sign of old age. You only have to replace the maintenance kit every 300,000 to 500,000 pages.
CPC for toner (OEM HP retail) is about one cent per page.

Jim at Servicemax
Cleveland, Ohio