no, it is not expensive.
bought the side inlet carter half and the carburetor at Cycletech (Switzerland) when they had their 20% price reduction action for around 150,- Euro.
The big carter was a scrap carter for zero=)
Enlarging cylinder sit for 46mm Pinasco in the great carter half 20,- Euro( if I remember right)
And the Pinasco Cylinder for about 100,- Euro from EBAY.
So, maybe less expensive than a Malossi Reedvalve or Polini Evo:haha
greets,Ralf