> That's simply not true. You may get a certain amount of leeway, but it has to be reasonable.
Where have you seen this?
When I was doing consulting I could charge whatever rate I wanted. Usually around $200 but went up to $500 and down to $25 when doing a favor. Same type of work.
At the enterprise level this is even more common. Nothing has a fixed price and the same service can be sold at wildly different prices to different customers based on endless variables.