I think the best way would be to call the dealers in your area.The prices seem to vary depending on where you are in the country. My L3130HST was 19000 with 723 FEL 4 way valve and R4 tires.
Carver Equipment has some MSRP's on their website. My impression from reading lots of posts on TBN is that 10% off MSRP is a good price and 15% is a great price.
Here are the 30 Series prices, but I did not see a comparable page for the B Series.
When you get your best price, make the dealer throw in the
filters and fluids for the 50 hour service requirements, including Kubota Super UDT trans fluid. That will be worth a couple-hundred bucks down the road.