At that price, are you sure he's not quoting you on a DK65, the older model? If you can get an S for under $30K, go for it.
Another feature some forget about on the 65 is the ground speed PTO which turns at wheel speeds. Good for some users, useless for others.
The S model has a very improved Perkins engine. I've used a DK65S and found it to be an extremely good tractor. From the outside rear hitch lever, telescoping arms and stabilizers, front/rear diff. locks, the dash that tilts with the steering so that no matter what height one is, he/she can still see the guages well. There was a lot of good thought put into this model. It also has improved air filtration and AC/Heat system over the original model.
As Dargo said, there really is no comparison between the Kubota model and the DK65. With that price, I sure wouldn't have any question as to which I'd buy. Kioti.
John