Almost any consumer does not mind paying additional money for additional service. Why not enumerate the membership benefits, highlight the new ones, and share that with the members, too?
You'd be surprised how many people know EXACTLY how much they have been paying for membership. And they can tell you how much membership is at other places, too!
Be careful of membership programs that cost more to deliver than you get in combined cash and good will. When you lose money on every transaction, it's hard to make it up on volume.
Liz Bleiberg