Old Price and Net PRICE confusion (OCC-412)

[infofromca]

Describe the bug

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To Reproduce

Steps to reproduce the behavior:

1. Edit 'Test Discounted Product'
2. Add 'Gross Price 20.00' and Tax Rate 20
3. tick Use Net Price Display of Price Display
4. See error

Expected behavior

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Screenshots

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Jira issue

[infofromca]

Detail page, better , but still confused with Price

[infofromca]

is it related with #397