I'll let someone else answer the price problem. I only played in DII maximum, and there are specific prices for DI, any answer from me would not be based on observation or experience.
Edit : and i've just realised that you are in DI already, my answer on the champion boost was really about being promoted and i've no experience of any boost for a DI champion....sorry if I mislead you.
Last edited by boule at 12/4/2016 12:35:26 PM