Testing an e-commerce mobile application,

I have the following problem :You're testing an e-commerce mobile application, similar to Amazon, ZOOT, eMAG, etc. A 2 week long sprint has just started and the goal of the sprint is to differentiate product prices between user types. The application already has all the typical e-commerce functionalities up and running ( register => log in => find a product => add to cart => order a product => order history ). Requirements: - Prices should be calculated and displayed according to the user type on all pages: Product page, Shopping Cart, Order, Order History.

My question is : Knowing that the execution and validation of the regression test suite will take 3 days, and the feature will be implemented by the developers in 4 days, how would your test plan look for the 2 week sprint?