Basically he has got a load of mapping files that you can use to map your own car providing you have the mean to do it. Take upsulote software for one, the disc will have say 5 different maps that you could flash your ECU with providing you can flash your chip as like mine it had to be soldered out and a new chip installed as it could not be flashed.
I would say for £17 is a bargain for all those maps and hay if you master how to sort it out on your ECU you could do a few for other at a small price.
Or we all chip in and by a copy of you so that you get back your £17, why don't I buy it and sell copies for a £5 each as you also get apps like VAGCOM from the sound of it.