There is a couple of places that buy some of the ink cartridges or you might take in 10 a month to Staples and get a store credit, might be other places do that also.
http://www.tonerbuyer.com/index.html
http://www.inkjetcartridge.com/selusyourem.html
If the printers have slots in the front for memory cards, then the boards are medium or high grade because of having memory on the board. If no slots then the boards are just low grade.