Price change for subcriptions...how do you do it?

[JoeZ]

I have prices on one of my sites set, and there are around 30 members who have a reoccuring subscription by month. I want to change my pricing structure for all new members, but keep the same monthly price for those who have it now.

I created two types of subscriptions, one with the old prices (and left it active), and one with new prices (but left unactive so far). If I deactivate the old pricing, will it continue to honor the old prices and just stop allowing new registrations?

How can I do this pricing change properly so my old members aren't paying the different prices.