As said eariler on in this thread, Lifeshine, Supagard etc are really only for people who dont clean there cars that often. It's never going to compete with a good properly applied wax.
The previous poster got it spot on saying that it's best to let other people have minimal contact with our cars. I know a few "valleters" at large dealerships who are still using sponges and chamoises on new cars. Most are paid very little, and have not had any sort of training in the art, so it is very unlikely that they are going to do the sort of job that we would be happy with.
If you are detailling your car yourself on a regular basis, you are more likely to spot any new defects and deal with them straight away. This would not be the case if you were only giving it a quick wash now and again beacause you were relying on the dealers treatment to protect the paint.
As for the cost of it. I know of many people who have had the treatment done when buying cars and said they have got it for free. However, the dealer has told them that he cannot discount the car any further, but will smear on products that should normally be charged out at £300 instead. Not exactly free then.
