For large values of B, in B2B, employees have corporate cards, with discretionary spending, so that's something to consider. A SaaS product with annual purchasing, priced just under the discretionary spending limit (read: an employee can buy this and their boss will just rubber-stamp the request and not even give it a second thought), is far easier a purchase. However, if corporate has to get involved, the effort is approximately the same wether it costs $1,000 or $10,000 because a bunch of people have to get involved, committees formed, and studies done.