How does it compare with the "Build My Kubota" pricing found on Kubota's website for the same exact configuration? If less than 10% I'd consider it a good deal.
Are you getting the self leveling loader valve or any of the cab options (wiper, defrost, etc...)
Someone else was buying a similar tractor and was debating on using the radial R1 tires and Cast Wheels. Not certain if they would be beneficial for your situation.
Added in edit:
Here's the link to "Build My Kubota" for your convenience.
https://apps.kubotausa.com/configurator/BuildMyKubota.aspx?pgId=1&bmId=933&sId=126