Less than a tenner for a year - pretty good bargain compared to regular visa costs. Perhaps an ID card or something? Not sure how passport control or the airlines would figure out to prove one is eligible.
I thought a visa waiver is something you don't have to get because you're waived from having to get it? So it's a sticker in your passport that's basically a visa but they say it's not a visa? A free visa? These are often bilateral arrangements but If I've understood it correctly, the UK could sure learn something here i.e. there is no need and no justification for making close family pay heavy financial penalties, and jump through lots of silly hoops for years, when the net result will always be the same.