Don't forget that elevators are very energy efficient. Properly counterweighted, the energy required to lift your car (or, conversely, the counterweight -- dependent upon whether you're moving the car up or down) would be considerably less. My physics is quite rusty, but I'm fairly certain the costs are closer to the work to lift the weight-different and the work to overcome friction. And make no mistake, these suckers will be counterweighted to match the weight of your Bentley -- costing the building owners less in maintenance and energy costs, assuming you don't pay those. Without taking friction into account, energy usage would be closer to:
Work required to lift 70 kg (let's call that the average weight of your tycoon, minus gold bars) 50 meters: W = 70 * 9.8 * 50 = 34.3kJ
Work required to lift your car every day for a year: 12.556 MJ.
But all this is moot anyway -- it'd be very close to exactly the same as that same tycoon just taking the elevator.