i went into redline a few weeks ago, looking around for my first skyline...however, i've been lurking round for a while checking out prices, and yeah they did seem a little expensive, 2-3k more than other places.
also, you'll be kinda hard pressed to find a GT-R there. the only one i saw was an R32. a lot of 32 and 33 GTS-T's, and most of these were pretty clean.
they're pretty good if you want a supra or 180sx as well, and one thing that i did notice that the brakes on a lot of the cars were very rusty, so that's something you probably should take into consideration when you look to buy...brakes aren't cheap.