If they did the same things I would better understand your dilemma.
But isn't the first a bluray player, the second a changer and the third a modest CD only player?
What system do you have, and what do you need to be able to play? And if not in the UK, what are their prices in your location. For example, in the UK, the Oppo costs about twice as much as the Rega, so not really comparable at all.
It's a bit like asking do I buy a Mini, a Golf estate or a Merc SLK!