If you think shops are making 50% on these parts, you're out of your mind. They have to compete with online retailers, who will frequently sell items at or below the costs that shops can even get the goods wholesale.
All the bikes I've seen being sold at RRP are the same in shops and online give or take a few £, plus you picked the top end of the range which I'd expect is only on smaller items.
I doubt online retailers are discounting items below what shops get them for wholesale but I'd be happy to be proven wrong. Wholesalers don't sell goods to shops with no margin on them or the shops wouldn't be able to exist.