Preserved Pricing

I've been publishing an app with auto renewable, in app subscriptions for purchase for nine years.

I'd like to raise pricing for new in-app auto renewable subscribers but grandfather (preserve pricing) for all our current subscribers forever. Only the newest subscribers get the higher price.

How long does the grandfathered price stay preserved for?
Hi! We are wanting to do this too but the person who is helping us with our app says this isn't possible. How do we preserve the old members prices?
Preserved Pricing
 
 
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