http://www.ebay.co.uk/itm/Genuine-mk-7-5-Golf-GTI-diamond-cut-alloy-wheels-18-034-brand-new-mk7-VW-5x112-/282508092972?cp=1&sojTags=bu%3Dbu&bu=43130221776&euid=6c8415bf5fb24d65af9976737feafeff&nma=true&si=royhJprdiO1ND5q51ii8jogbJcM%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557Thats the only set of Parkers I have seen sold on eBay recently - I spent the last few months looking for a new set of alloys and remember these coming up in a saved search I had.
£363 sounds like a bargain to me - someone with a normal Golf did well there.
Slightly off topic, but still on the subject of Parker alloys; the standard wheels for the 2018 new model Polo GTI is a 17” version of the Parker alloy , with an 18” version of the Brescia as an extra cost option.