So on the basis it's done cheaply it suggests that prices in the UK aren't a rip off 
Not necessarily. Most large retailers and suppliers to consumer markets (and I mean that in the broadest sense, from Tesco to BMW cars) want to capture as many market segments as possible, based on what segments they believe exist or can be created.
Asda, for instance, has its basic level brand. Can't remember the name offhand, but you can buy a whole chicken for 1.99. And then they have the mid-brand stuff and then the 'extra special' line for what they see as the top end stuff. Tesco does the same, as does Waitrose and so on.
BMW too. Their range covers every possible type of car that someone might want, from a 2-door sports job, through various family saloons and SUVs to its top end 7 and 8 series lines.
In order to do this, some companies have to almost lose money on the cheaper lines, and then pad the prices of the expensive lines to compensate, and to ensure there's a real as well as a perceived differential.
I'm sure there's a word for it in marketingspeak, but I don't know what that is. But it means sometimes we think we're getting a ludicrously good deal and other times we feel ripped off.
Same with train tickets. If I book in advance to go to London from my home town, I can get the fare down to under a tenner if I go off-peak with a railcard. But if I show up at the station and want to go NOW, it could cost me over a 100 quid for an unrestricted first class one-way ticket.
All this makes comparisons, especially with other countries where this sort of malarkey doesn't go on to the same extent, difficult.