VW Racing is nothing to do with Volkswagen AG, and their parts are not offered at dealerships. It's an aftermarket company who recently rebranded themselves to 'Racingline'. Probably because VW AG didn't want people thinking there was an affiliation there!
This 'pack' is a rebranded ITG Maxogen intake, Scorpion or Milltek exhaust and their own remap, which is actually done by people in Eastern Europe, not Racingline.
APR did manage to get into a few dealers in America, but the warrantied remaps are significantly lower BHP than their maps sold through the aftermarket. I wonder why
Anyway, if the mods on the cars you are looking at are of a known provenance, and there are no obvious signs of abuse, then substantial savings can be made. If you were thinking of a Revo map anyway, it doesn't make sense to get a stock car and then add it yourself. I know there are lots of boy racer 'pops and bangs' type modifiers out there, but at the same time there are also people who like the stock car and just added a decent map and decent suspension.
Avoid cars with budget mods and you'll be fine. Everyone likes standard, but some people ask stupid money for original cars. Just go in with your eyes open and intuition. If something doesn't smell right, move on to the next one.