For someone with an Sti already in hand and looking to "down grade" into a swappedRS....you could purchase an 25RS. complete the drivetrain swap. kep the interior though. Put the running 25RS motor trans and everything needed to run/drive into the Sti. Take it to carmax. where they will low ball you anyway but say they offer you $10000 for it that is still probably more than the cost of RS and swap. Most dealership and appraisers have no clue about the actual car and base their appraisal off VIN and condition. they will see sti interior. probably never notice its a 5 speed. and never even heard of brembos. this is all hit or miss. but if your going to do a swap anyway. why not give it a shot.
I just had this thought after many experiences with salesmans and dealerships not knowing jack about cars
-a saleman at a mazda dealership told me a mazda speed3 will run 11sec 1/4 mile with a Cold air intake.
-when i sold my STi the front bumper spats/canards were ripped off from Rally x and have quite ugly holes in the front bumper. he asked if those were custom brake coolers. This was a sales manager from a Cary subaru in NC.
-I went to check out a JEEP SRT8, I typically play along and ask questions as if I didnt know that much about the cars. So the salesman dont think Im really coming there to flog the cars.I am. So i asked if this jeep was 4wd. i knew it was. but he said it wasnt. OK
Really whats with salemans these days not knowing jack about cars.