How to properly set up an online business?

It’s my first post on HN so please pardon any mistake I might have. I'm planning to start a small e-commerce business with a few close friends, specifically selling handmade cosmetics. Judging by our target market, we think the best initial approach would be selling through social network channels like Instagram. However, our main concern is this road will be very difficult to scale later on, and maintaining the sales for a long time will be very difficult. The page will eventually die out sooner or later, like many similar business that only based on Instagram store in my country. So right now we are stuck between 2 choices:

1. keep going with just an instagram page and see how it go.

2. kickstart an e-commerce site with our product listing, customer support, payment gateway,… I am thinking about using existing platform like Shopify here.

I feel that going with 1 would be very cost effective and can produce revenue instantly but 2 will be better for us later on. However I can not see any other obvious drawback to simply decide with just this, any insight would be extremely helpful here