Hi,
That is an interesting use case. So you would need some sort of system that links this membership perk to individual user accounts, so that discounts on items are automatically applied upon logging in. This sounds very feasible.
For the part where you mentioned about showing the total savings “before the user makes a purchase”, it’d be great if you could emphasize on where you would like this to be displayed. This is because if you are looking to display this information at the checkout, then you would require a Shopify Plus subscription. We might be able to add a dashboard or snippet displaying this information on the store page instead.
What you are describing sounds pretty niche. I’m not sure if there’s an app available for something like this. Either way, if you would like to speak with us more on the requirements of the app, we’d love to help. This is definitely something we can build into a customized app for your client. If they are interested, feel free to book a free consultation at shypyard.io. We are a Shopify Expert-certified agency that helps Shopify merchants with these kinds of app customization. Looking forward to meet!
Cheers,
Courtney