I was talking to a motorcycle dealer that I did business with and we were discussing trading in used motorcycles. He kind of let it slip that some people expect as much trade-in for a late model motorcycle as what he can buy a brand new one from the factory for.
I don’t know what a Kubota dealers pay for a new tractor from the factory but he is likely comparing that to what he is offering for your trade-in, not what you paid. Of course he can sell the new tractor for more than your used one so he must offer less for your used tractor even if it is in like new condition.
When you sell it yourself you are dealing with people who are looking at it from the same place you are, the customer, so a like new tractor for a couple thousand less than new might be appealing, depending on the person. Some people like buying used, others would rather spend the extra for brand-new.
If you have a popular item in like new condition, you probably will have little trouble selling it yourself. I have always sold my used vehicles myself and saved at least a thousand dollars each time.
As has been stated, be sure to consider the difference in taxes when setting your selling price.