Umm... I don't know the types of beans! If there's more than one, let's buy all the different types, and then we can test out which ones'll grow the best!

[ ~*~*for science*~*~

There are different types of beans in general, not just soybeans, so if Yamato has the budget for it, she insists on them buying one of each pea/bean/lentil/whatever in the store for the shopkeeper to have to make up a bulk price because they sell by weight. ]