depending on were you get your parts from. the most expensive thing on that list would be the injectors. then the exhaust. or vice verse.
http://www.toyota-supra.info/forums/...t-a-supra.html
that link talks about upgrades and gives some just random pricing on injectors to give you a feel for whats expected. you might as well throw on a 3" turbo elbow and exhaust header to that list. if your gonna do something, might as well do it right.