If both cars had axactly the same power numbers, the S2000 would definately walk the EVO because it's a shit-ton lighter and rear wheel drive is easier to launch. And anybody who built a 500hp S2000 and wouldn't build the entire drivetrain (trans, readend, alxes etc) is just a moroon!
But to answer the original question, the EVO would have the cheaper build since it is closer to the 500hp mark and is already turbo'd.