I'll struggle to believe Kubota would leave off $200 worth of lights, step, mirrors and deduct $2500 from the price.
I don't. Some car companies will "leave off" the cruise control - consisting of the $20 stalk on the steering wheel. The computer can still do cruise. If there's a competing tractor at a particular price point, and they don't have one at that same price point, they need to make something fit. But they don't want to just discount the tractor they already have - lots of people are paying full price for that, so you'd be leaving money on the table. So you make a "new tractor" that is less attractive to those with cash burning a hole in their pocket, but is good enough for those who $2,500 difference is important.
It's very akin to home brand cornflakes. They're usually the same cornflakes, just discounted and in an uglier box. The marketers call it market segmentation.