Are you able to evaluate the level of investment required, in monetary terms, time and effort?
In order to clarify and build the business case for your CRM project, you will need to have an idea of the investment required.
If you have defined your outcomes well enough, a good CRM vendor should be able to give you some indicative costs of what would be involved. Ask providers to talk through similar projects with you so that you understand the scope of such a project and who would do what etc. Make sure you understand what resources internally you might need to deliver the project. All will need to be taken into account in order to define the cost / investment required for the project.