Managing Membership price increases and DDs

Hi

What's the best way to implement a price increases for Membership Levels within a Membership Organisation? Request is for change as of 1 Jan. We are due to run the DD renewals for January imminently - how do we run these at the new prices, whilst keeping the old prices for new sign ups until 1 Jan? Or do we just have to change them as of the renewals ie now?

Any thoughts welcome!

many thanks
Best wshes

Dawn