Prices from 2018 and any other year are fairly irrelevant as the price can change overnight. It's simple enough to build your own tractor on Kubota's website including options. From the list price the OP can figure out what is consider fair. If you can get 10% off list, some might consider this awesome, but each individual is different.
One needs to be very specific with the options as there are many and the price will differ as a result.