Well, to be perfectly honest, I don't think "Good" and "cheap laserprinter" have anything to do with one another.
Anyway, I just recieved an HP LJ 1200 for a client. It would work well with a jetdirect box. If you can afford it, or if it's for a business I would strongly recommend an HP 4050N. It's a wonderful rock solid network printer.
If you're sending 500 page documents to a printer on a regular basis you shouldn't be using a $500 printer.