Used HP5si, if you can find one. Bought one that was about 8 years old, going on 6 years ago. It doesn't like really, really large PDF files, but it just keeps on chugging, and the toner comes out to something like 0.1c/page. I got mine for $220, plus another $120 shipping, on ebay, and it needed a $100 fuser assembly to get the print quality looking good. They haven't been made in years and years, and aren't even supported by HP anymore, but there's a huge installed base, and lots of vendors with parts.
If you're willing to go inkjet, have low volume, and don't mind some idiosyncrasies, there is a Brother 6490 I picked up for about $250 last winter. It's real bonus is that it's got an 11x17 flatbed and document fed scanner, and can scan directly (color or b/w) to PDF onto a remote server. Not a perfect solution, mind you, but not bad.
Jordan
Bill Cain wrote:
My HP9800 is an inkjet, not a laser, but it has been a solidly performing workhorse for several years now.
Regards,
Bill Cain, SE
Berkeley, CA