No, at this time the Shipping rate for a product cannot be adjusted here under Pricing Rules. That said, you are able to adjust the value of the shipping rate in your Shopify/BigCommerce admin.

As a friendly reminder, for both Wish.com and Modalyst Marketplace products, the shipping rate is determined and controlled by the Supplier. That is to say, if you adjust the Shipping rates in your Shopify/BigCommerce admin, please cross check that change with the Shipping rate quoted under Import List > Pricing & Profit on Modalyst.