I have developed and piloted a costing tool (PSROI) in 5 subsistence-farming communities in Kenya, Senegal, Vietnam & Laos. See http://ccafs.cgiar.org/sites/default/files/assets/docs/ccafs-wp-16-psroi... and New Agriculture article http://www.new-ag.info/en/focus/focusItem.php?a=2619.