I'm not sure how big actually the business discount is, I've heard it is between 4-6%, $500 off on configurations below $10,000 is actually pretty good/similar discount.
Don't forget that B&H offers its own credit card, after instant approval card can be used right away, that "eliminates" tax. This for some, is additional savings of over 6%. Another advantage of buying from them, is that some configurations are already in stock and can be picked up the same day. No need to wait over 2 weeks, as it looks like Mac Pros are being delayed:
https://www.macrumors.com/2020/02/12/new-mac-pro-shipping-delays/
Free, expedited shipping too.