You can bulk update products via import using the object ID.
To get the product ID of your products you can export them again once they have been imported. You need to go to your product library, tick next to each product and then select 'export' in the toolar.
Once you do this, you will have a CSV file with all your products and their ID. You can then edit the price vales on this filel and import it.
When importing the file, set the 'product ID' as the 'object ID' at the mapping stage
I really hope this helps!
Olivia Bagnall
Inbound Consultant | HubSpot Specialist | Community Champion