Discounted price and purchase prompt on iOS App Store For a couple of days, I have been getting this issue with my iPhone. For some Apps, It says 


  This discounted price is only available to customers who own a previous version of this item. To purchase this item at full price, click buy.


while trying to update it. How do you make the iOS device  update the apps.

Additional Information about my phone:
iPhone 6+
iOS version 12.4.1
App Store Australia
I have this same problem on an iPad.
If I uninstall the app I'm able to install the new version - but like you there are 10 apps I have this same problem with.

My suspicion is that these apps were installed when the iPad was setup to use Apple Account "A". A number of weeks ago I switched the Apple Account of the device to be account "B". So I think the problem is that the app store is preventing an app, installed by "A", being upgraded (for free) by "B".

Is anyone able to confirm this hypothesis?

UPDATE: Yes, this was my problem. I used the old account within the App Store and I was able to update those 10 apps.