Interesting - I asked my dealer directly who was responsible for the price increase, them or VW, and he said (in writing) that it was VW.
I also asked him where in the contract it stated they had the right to vary the order price, but he conveniently ignored that question.
I will be contacting VWCV tomorrow, despite there being sod-all chance they'll reduce or remove the price increase (according to my dealer). The least I can do is ask the question and then let them know how I feel if they refuse.