Let me know how you make out please. I also have a B6100DT that could use a ROPS.
I just received my quote for the ROPS and seat belt kit from Kubota. Here is the breakdown for my B6100-DT
2-P ROPS..................................$148.00
Estimated Labor.........................$158.00
Shipping and Handling................$ 90.00
Tax...........................................$ 23.76
Total Price.................................$419.76
Dealer Installed Promotional Price $299.76
It looks like Kubota discounts the kit and the installation by a good chunk of change. Now let's see if the dealer goes along with it. If so, I'll have the dealer install it. I'll also ask about adding the kit to the dealers stock order, but it appears the discount may have already considered that, and then some.