People used to buy HP Laserjet 4 printers at auction because they were peak stability. From the look of things the 4 introduced the direct predecessor to the wire protocol printers use today (PCL 5e vs PCL 6 variants)
There were a ton of companies selling refurbished or knockoff toner cartridges for those things too. As good as the LJ was, the fact that they had easy access to cheaper supplies just accelerated the process of selection.
