UK X51 People: Where on earth did you get the R1 to R2 Powerboard upgrade from?

Hello all.

I am one of the million, sadly lumbered with the R1 X51 and watering at the mouth at the prospect of upgrading from the GTX 660 to the GTX 970.

I have however, hit a stumbling block. Whilst I know that I need a D85RT 'daughterboard', i'll be damned if I can find one at less than around £150 (!). Seemingly, our more fortunate American cousins are paying the equivalent of around £40, a whole lot cheaper than I can find in either the UK or Europe.

So, fellow UK people, where can I find a D85RT at a price that won't make my wallet cry?