It's very hard to determine a price. Especially if you searched areas like Tractorhouse and couldn't find any comparables. In my area, if you can get 70% of what you paid new, take it.
I started with a B2910, then bought a L4400, now own a M9540. Try really hard to look long range at your future needs and buy the tractor that best suits those projected needs. In my situation I should have bought the M model when I bought the L. But my needs were growing. Yours might be static.
When you determine a price, come back to this site and run your advertisement. Might pick up a buyer here. A LOT of Kubota owners on this website. Good luck and welcome to TBN.