The M120 V12 600SL is admired as the flagship and started around $125k new, but owners caution it costs more to maintain than the V8 cars, with wiring harnesses said to be far harder to source than for the 500. Gen-1 600SLs with good mileage are noted as not getting cheaper.
V12 600SL: grandeur, but costlier to keep
Mercedes-Benz SL (R129) · ownership