This is for all current model BX and B-Series tractors. The reduced price is only available to an initial dealer ordering of these seats, the normal price is almost $200. Don't expect to see one soon, they are first being applied to production units, then to stock machines, then replacments for existing units and anyone else who wants one. The B2630/B3030 come first, followed by BX's and then later in the year the B7800 and older BX's will come. It will be 3-4 months before you see them in volume.
I am not sure how they are quoting an exact price at the moment, it will be very inexpensive, but we won't know an actual price till we find out what the freight and installation costs are.
My butt had the privilege of sitting in one of the new seats. They are a huge improvment over the old ones. In Kubota's words, they are taking somthing thats been a complaint and turning it into a positive feature.