For me the indian variant is not sooo interesting :
1580 $ = 1215 € + shipping + custom + import TAX (VAT19%) = appr : 1500 - 1600
the direct polish quote was 1614 € : no import tax , no custom for me ( + transport , or drive 1000 km by myself)
for my plans to built a Combined-Heat-and-Power System the S321 with 27 HP was my favourite , because it was the "biggest" single cylinder still in production I could find.