Interesting idea, itemised receipts have also been discussed here 
but this is the first time someone’s suggested charging users to receive that data.
I’m not really a fan of the idea to be honest, obviously the same information is free when it’s on a receipt. It would be key for budgeting too (for breaking down purchases by category) & I’m not that it would be a very good user experience if users had to pay to access it. I don’t like the idea of some users having access to certain functionality & not all either. At the moment all users are treated equally & I’d hate to see that end. That’s just my opinion though 
You could ask the team from Flux what they think…