The Xerox M20/M20i printer, copier, scanner has a purchase value of $299, since this is a discontinued model, a used one with the network card already in it can be purchased for this amount in full.
The network card kit for the Xerox M20/M20i costs $269 to add this feature to an existing Xerox M20/M20i printer, making a Xerox M20/M20i printer without that feature effectively worth only about $30.
The recommended path is to replace the printer, copier, scanner with a newer recommended Xerox network printer model specifically for the features you're looking for and in fact becomes less expensive from a total cost of ownership standpoint, as the base price is $229.