What if you sell a product where it's easy to determine the cost for one user signing up by themselves, so you figure out the required markup and publish that on your site. But large organizations wanting licenses for each user will want a discount, will want finer details about contracts, and often some kind of unique adaptations to the product for their use case. The selling company needs to know if its worth the effort, in which case you have requirements gathering and negotiations. Of course there will be differential pricing depending on what the buyer company wants (cost goes up) and if it's a whale of a deal that the seller really wants (cost goes down) So... schedule a call?