Totally agree regarding the Cottage Group's massive margins (especially on bottles) - it's often bordering on crazy. However, they are leading the market in terms of selection, so I guess they can justify the 'you get what you pay for' thing.
But 5.50 for their own brews (which are fairly average IMO) is just wild. Sweetman's core range are far superior and they're only 4quid a pop. Was chatting about this with a mate the other day, and I think the Cottage Group have raised the prices of their own range to make up for all the free pints they give away (in exchange for cinema stubs, concert tickets, etc). I wouldn't drink their beers at those prices unless there was a marked improvement in quality.