Or make counterfeit memory out of cardboard, or balsa wood, or something. It'd almost be an entertaining weekend project to cut little pieces of wood in the shape of DIMMS, then use Testors paint to put down a green base with little square black chips, and shiny silver metal legs. It'd only take an hour or so.
The enclosed note would read "Your memory should work as well in your machine as your money did in my economy."