I need to track revenue to some analytics services server-side when receiving App Store Server Notifications about subscription status updates. But response body from notifications and from verifying receipt doesn't include price info. Is it possible to get the price of the transaction on the server? Maybe is it a way of validating transaction ids or something like that? Currently, I can get the price and currency only client-side in the app from products info?
I don't think you're able to get the price of a transaction via apple notification or even when validating a receipt. But you do know the product_id via notifications, so you can just look up the price of the product.
For old transactions with products that have changed price I do not know how you would be able to get this data.
Sales information is available through App Store Connect Sales & Trends dashboard. StoreKit transactions and receipts are intended for entitlement and status and not revenue reconciliation.