The Revmax option is the best remanufactured value out there (BMW remanufactured is over 2K) compared to rebuilding the transmission valve body on your own. Just the parts alone are $400 + (solenoids, gasket and sonnax zip kit) and the cleaning of the valve body and machining of the mating surfaces based on the process described on their site seems to beyond a DIY project. The Sonnax zip kit seems to address a lot of the inherent issues with some of the internals. Most of the internal rubber seals are in need of replacement by now anyhow.