This is a great source > https://www.odoo.com/forum/help-1/the-almost-complete-guide-to-pricelist-behavior-185877.
Good practice to be able to raise prices in bulk by percentage
Add the prices of your products to a newly created Base Pricelist and derive the Public Pricelist (and/or others) from this pricelist adding the percentage. (You need to enable the 'Advanced price rules (discounts, formulas)' setting for this.)