The specification may ask for a car, but when you do not know if this is a Mini or a Rolls Royce you can consider option pricing. Giving alternative solutions, or a solution with optional extras, means you retain flexibility to negotiate.
[jetpack-related-posts]Flexible Pricing Strategy = Successful Tenders
Deciding how to set the price for a project is never easy. Ideally you will know the client’s budget and expectations in advance of writing a proposal but this is not always possible.