But as someone who's tried many varieties of Japonica, there is a difference between the best Japan-grown rice and non-speciality rice grown elsewhere, as well as a difference between fresh (Japanese enjoy eating new rice, which is different from many rice-eating cultures) and old rice.
I pay somewhere around AUD$14/kg for Japanese rice in Australia, but I also don't eat it that often and I'm not that price sensitive.
But also, the average Japanese eats around 1kg of uncooked rice per week. That's ¥800 at the rates in the article (~USD$300/year). Japan's cost of living is generally pretty low, but I doubt +/- $100/year is effecting many people.