You can create a unique insurance price and change the customers subscription to that unique price.
Select the insurance option in the left hand menu, and select Edit on the applicable cover level.
Then enter the required price and hit Update cover level.
This is creating a record of the new price so we can select it when editing the customer's subscription. Repeat this process to replace the price with your storefront price.
To change the customer's insurance price, click into the customer's subscription, and select Edit Insurance. Select the newly created price, and choose to start immediately or on next renewal. Select Preview changes and then Change Insurance to save your change.