I've had mine for just over a year now and bought it from someone advertising it on clubgti - but they didn't advertise it anywhere else and I think he waited quite awhile before I came along.
I always find it best to just blanket advertise everywhere - gumtree, ebay classifieds, forums, fb marketplace - annoyingly there doesn't seem to be a separate section for ED30 GTIs on autotrader, so you're lumping it in with all the bog standard mk5s