can anyone explain why a Lutron Rania dimmer with the B&O code is over 3 times more expensive than the standard Rania? 

Because they are produced in much smaller quantities, and they need to make back the costs associated with delveloping and producing the product?

I'm in the process of purchasing a few myself.

A word of warning, the price charged by UK B&O dealers varies HUGELY (over 100% difference)!

The differences were explained to me as begin because a few key dealers have a special relationship with Lutron (they sell their systems along side B&O). They have been given preferential treatment in terms of stock, so they are holding most of the UK stock at the moment. They are then adding their premium, then selling them on to other B&O dealers. They are in turn adding on a profit margin for themselves, then selling them to us!

The result - super expensive Rania's from some sources, reasonable prices from others!!

If ok with the moderators, I'd like to see a thread where we all chip in our local price. Since most dealers seem to have no issue posting these items to customers, we could all then order from the cheapest one! 

I get the impression that as B&O fans we are expected to pretty much accept our local price (subject to a little light negotiation). I tend to shop around for most of my electronics - B&O is no different!

recoding the switches in my opinion to b&o would be negligible for lutron for the sales it would generate, i can get the standard ir rania dimmer for 54 pounds, ive been quoted 170 pounds by B&O! anybody found them any cheaper? 

It might be obvious for most of us, but if you already have a Lintronic converter, you won't need the B&O version of the Rania dimmer, I have the normal IR Rania, and with a Lintronic box it works well. The only limitation is that the Lintronic converter still has no numbered keys for "light" (= you can't select "light 1 or 2 etc...just up or down).