The most expensive wax is about 7000.00 dollars but the best thing to do is to go to www.autopia.org or www.autogreek.net for great information on how to get the best possible shine and wetness for your ride.
The best wax is Cherry Wet Wax. I have seen it do wonders on a black car.
http://www.coatsproducts.com
If you are ever in Pa check this place out. Ask for Brad.
http://www.autospaofwyo.com/