Your negotiations at the car dealer are usually based on some source of facts. Edmunds pricing, Consumer Reports pricing, and similar sources of cost, margins, dealer incentives, local market conditions. Negotiations are always successful, when there is a mutual beneficial outcome. For the dealer he moves a car, stops paying on the 90 day note needed to put the car on the lot, and you get the car at an acceptable cost.

If you accept that estimates are for business decisions more often than they are for developer decision, then facts are needed for a negotiation to have any mutual beneficial outcome for the business and those provided value to the business in exchange for the cost of that value.

When there is no “basis of estimate” those asking for the estimate have no “basis” on which the judge the estimate provided by those being asked. This is not the foundation for a mutual beneficial outcome.

When the developer says 5 and the asked says “I need 3” AND there is no basis of estimate for either 5 or 3, there is no means to actually negotiate and the results is those paying have the final say.

Until those being ask come to the table with credible, verifiable, statistically sounds estimates, this relationship will never change. And those consuming the money from those providing the money need to provide credible estimates. So those providing the many can make credible decisions.