530
HP CEO: You're 'bad investment' if you don't buy HP supplies
(www.theregister.com)
This is a most excellent place for technology news and articles.
You can buy 3rd party toner for Brother and they don't lock you out of your own printer for doing it.
On brother printers, if the printer says toner is out and you can't print, you can press a key combo on the printer to reset the toner page counter and then continue printing until there is literally no toner left at all.