Version 2.100 and up

Instead of manually creating a new rate card with all it's ad prices ADvendio offers you a clone button which directly copies rate card with all ad prices. 

Here is how to use it (make sure you administrator has enabled this button to the correct users).

You will receive a message stating that your rate card gets created and receive a message when done. Afterward check your newly created rate card and update the rates. 

Modify Ad Prices

An easy way of updating your prices is to use list views. In Classic or lightning Salesforce allows mass editing. Therefore create a list view with a filter that shows the Ad Prices (Example: all prices belonging to one Rate Card) you like to modify and then change and save.

Or even mass update by checking the update x selected items checkbox:

Alternatively you can use the 3.3.3 Create and Update Rates Wizard.