This depends on whether you are running your price test using Checkout Scripts (typical for Shopify Plus) or Duplicate Products (typical for non-Shopify Plus).
If you are using Checkout Scripts, Intelligems updates the price in Shopify to the highest price in the test and sends that price to your shopping feed. We recommend triggering a feed update once the test is live, especially if you push your updates to the feed manually or if you use an app to manage your Google Feed. This means that for visitors coming into your site through Google ads, they may see a lower price when they get to the site, but never higher prices.
If you are using Duplicate Products, Google will continue to display the control price in the Google Shopping feed, which means users may see a different price when they get to the site. We recommend sending the higher prices to Google so that if users do see a different price when they land onsite, it's a lower price and therefore better for the customer experience. To do this, the original, non-duplicate products must have the highest price points in the test. This corresponds to the column on the left when you are setting up a test in Intelligems. Additionally, you will want to make sure you remove duplicate products from all third-party channels so that the products don't show up on Google multiple time with different prices. You can read more on how to do that here.