How to determine the budget for a Scrum project

Hi. How can I determine a budget for a Scrum project? What parameters should I count to estimate the project price? My issue is I have to submit a project report to the management for implementing Scrum and give an estimate how much the project is likely to cost. I can work up a development budget, but the main issue is the Sprints could extend if the management wants changes in the product features over the project time. Thanks in advance.

Posted By - ross