The mfa Yamamoto is an old design. I built one as my first power plane back in the early 70's. It had foam obechi sheeted foam wings and was only 3 ch ( no ailerons). The wing has a thick section and blunt leading edge and so is quite stable. I still have the original plan. As I was converting from slope soaring to power I reduced the dihedral and added strip ailerons. Power was a plain bearing Enya 40.
It flew fine but was a little too slow and stable for me. I sold it to a new club member who sucessfuly learned to fly with it.
A word of caution regards the MDS engine. The quality of these is quite variable - some good some very bad.
Sorry I can't help you with the pricing. I've lived this side of the pond for over 25 yrs and so am out of touch with UK values.