If there is no need for newer features like bluetooth printing, cloud printing etc and the current Xerox machine is still reliable and rarely jams then it might make financial sense to continue using it.
Personally I would switch to a newer machine only if the older machine’s TCO (total cost of ownership, ink + parts + servicing + depreciation value) is higher per year. Especially if it is breaking down or jamming more often or there is a greater need for newer features.
I still prefer Xerox Versalink machines with stapling function.
If you want something even cheaper but with similar Laser like printing quality, you can look at the Epson WorkForce Pro WF series with PrecisionCore and Durabrite ink series of inkjet printers. Their new PrecisionCore printhead technology is pretty innovative. Note that their ink replacement costs can be higher than traditional inkjets. Their Durabrite pigment inks on printed paper can last 120 years.