Hank here from Shopify.
I am not sure about the site you referenced, but if you are querying about the cost of running a Shopify site, our plans start from just $9USD per month with our Lite plan.
With that plan, you can sell on the likes of Facebook, with the buy button, create custom orders, and more, but if wanting one of our plans that comes with an online store, they start at $29USD a month. This page gives you a full comparison of our plans and the additional benefits that come with each plan to assist with your store's needs.
Let me know if you have any additional questions!
All the best,