Alternative to shopify?

Hi guys, I need a part of my site to be e-commerce. I am selling online PDF documents, like Ebooks etc. I wanted to use Shopify as the sites I am looking to copy their style all use Shopify, so it’s easier as in Shopify has it’s own look and feel and you can just customize it with your logo and basically it’s all moreless done for you when someone presses buy and checkout etc.

I don’t want to pay a monthly fee though like Shopify does.

Does anybody know some other alternatives I can use for selling an e-product and having a smooth easy process just like how Shopify does?

I found the ones but I don’t know if they offer that type of all in 1 package like Shopify where it takes care of most things for you. Shopify literally you just have to copy paste the link into your BUY NOW button on your site and the rest is done on their platform and not yours, meaning you don’t need to build any HTML pages etc just for the shopping experience.

Or any others?