How can I determine the monetary cost of a user story point in a given team?
I was asked this question recently since the business is interested in determining how much a given project could cost them.
Now I know a user story point is a subjective measure of estimation, e.g. The team assigns T-shirt sizes to the stories: small (1 point), medium (2-3 points), large (5 points) and extra-large (8 points), etc. This estimation of the size is very subjective and if the team changes in any way, what they subjectively consider small, medium or large could change as well.
I know that after trying planning poker for a while, the team calibrates their estimation subjectivity and eventually this becomes evident in the fact that the team delivers (on average) the same amount of subjective story points per iteration: our team velocity.
However, the problem is that my team has changed several of its members recently, some of the new members don't know the domain yet and/or have less professional experience. We won't know our velocity for a while.
So, bottom line is that thinking in agile terms, I have no clue how one could determine the cost of a story point, or even following any other strategy how much a given project would cost.
Any ideas on what's the right way to do this using a formula that makes sense from agile perspective?