Re: 5 members agreeing on prices via a quasi trade body?
They've been gifted a monopoly by us (the UK). They haven't earned it. We should be able to take it back if they start taking the piss.
Originally it was sort of gifted by the UK's ISPs during it's formative years. It was recognised that it'd have monopoly powers, but government approved given there was competition in the rental of domain names. It was also recognised that there was an embarrassment of riches, hence the creation of the trust to spend some of that money to better the UK Internet.
So intially, ISP members outnumbered the registrars and could provide more influence/control, but then came the coup, change in voting rights and the big 5 ended up controlling Nominet and shaping it to serve their own interests. But it's the usual challenge with a 'non-profit', ie trying to justify charitable uses of all the not-profit it's been generating.
And then there's politics in general, ie Nominet has a large slush fund it can (and does) use to protect it's monopoly, and would argue government interference. But hopefully a CMA complaint might get some attention, and a hairy eyeball looking at Nominet's books to see if price gouging is at all justified. Then hopefully it'll get regulated, probably via Ofcom who could look at pricing much as it does for BT. Usual model is look at things like LRIC and regulate prices based on a cost+ model.