If I were to build something, I don’t want us to start out with a hypothetical discussion about total project cost or define a total project budget. I want us to decide whether we have found a problem we think is worth solving (yes, independent of the so far unknown cost). Then we start out small (MVPs, experiments, prototypes, sketches, whatever, think lean startup). We invest time and/or money in an attempt to prove that theory. After some time we will have more information available, and we’ll soon if we’re going somewhere or not. If we are, at some point even a discussion about total cost will become feasible if at all necessary.

If it becomes apparent that we will be able to solve the problem, we will probably have already started delivering value, and the value vs cost is obvious to anyone involved. ..Until we hit a point where it’s not, and then we simply stop and move on to the next problem.