I just can't understand the price here.

Buster Dagger Conversion

It is a kit to convert a 1/100 Buster Gundam into a Buster Dagger. It isn't even a full model yet they are charging more then the price for the PG Strike Rouge + Skygrasper for it. The PG Rouge is 19,000 Yen, the Buster Dagger conversion kit is listed at 19,800 yen.