HP do a very good range of multifunction laser printer/scanners. I have one that costs around £120 that I think is economical to use, not sure how many sheets per cartridge, but quite a lot and it's fast. It can be plugged into the phone line and act as a fax as well. It also supports the new HP "print from anywhere" function, but I haven't used this yet!
Another brand to look at is Brother, I had a very good Brother laser printer some years ago and it was very economical but I think they are more expensive than the HP.