Not much. If you feel you would want to reclaim anything from them, keep in mind that the synthesis produces 15g of MDMA.HCl, or 15000mg. After scraping the filters, there is at most 150mg of product lodged in there - if you are using real Whatman filters instead of coffee filters, it is most likely just a fraction of that.
150mg of a 15000mg batch is 1%. Or using real filters, it is probably more like 0.25% or something. Are you that cheap - go ahead and extract the filters with IPA, and evaporate the solvent. You will gain much more by putting the same amount of work into performing each previous step more carefully, and never take any shortcuts.