Cheap and very basic, from what I've read on UK Campsite, and not spoken very highly of by the small number of reviewers. Llyn Gwynant camp site scores much better, or is that too far away for you? Continuing past there if you're prepared, the National Trust Hafod y Llan site is very basic, and then there's Cae Ddu just before Beddgelert, which is excellent IMO.