Cal here from Shopify, thanks for reaching out to us. I'd be happy to help with this!
There are three ways you can add Carrier Calculated Shipping to your store:
The most popular options are 2 and 3. People who know they need CCS for their business tend to switch to an annual plan immediately, whereas those who want to test CCS for a couple of months tend to opt for the extra $20 until they are sure they need the feature. Let me know which method you'd like to opt for and we can investigate adding the feature to your store!
Sorry if I was a little unclear last time. The three avenues to have CCS added to your account are listed above in my original post. If you were to, for example, switch to the Annual basic plan today, you could request that CCS be added to your store for free. Or if you wished to opt for the $20USD a month add-on to your existing plan, then you could request for me to add that feature.
The Shopify Plan is our mid-tier plan, and it does not have CCS as a feature. You can view a breakdown of the plans and their features here. You could choose to switch to the Annual Shopify plan, and get CCS for free, or request the $20USD CCS add on for that plan.
It's totally up to you which plan suits your business best. I'd be happy to assist with whatever option you choose!