google sheets – Formula to Copy Paste (instead of Vlookup)

I have a very important issue.
Is there a Formula that works like VLOOKUP but does not change the values dynamically?
Instead of changing the values, it just copies and pastes the value each time the index (for eg. a dropdown) is triggered.

https://docs.google.com/spreadsheets/d/1G7MW1vTBREvyK6tNIaWja3M2Z7v7NpCoDB9gZgKWCYk/edit?usp=sharing

Lets say the price of a product changes after a few month and I don’t want to change all the prices in the sales sheet that have been sold..