Wordpress + WooComemrce is a great combination to use for setting up a store to sell digital products. Though it requires some technical knowledge, overall it results in savings.

My tech stack

1. Wordpress setup on AWS Lightsail - overall costs 3.5$ a month

1. Add WooCommerce

Go to Plugins > Add new and search for Woocommerce

Download and activate the plugin

2. Setup WooCommerce

Navigate to Woocommerce > Settings Then select the Products Tab

Disable the two checkboxes

3. Modify WooCommerce Product settings

Make sure the checkbox Sold Individually is checked under Product Data > Inventory

4. Locate the checkout page and copy the link

Find the checkout page and open it

Now on the right side of the page, copy the permalink

My perma link for checkout page is

http://35.154.187.243/?page_id=283

Navigate to the products menu on the WP dashboard and click on it My product ID is 300

Now add the URL params to the cart URL this way

http://35.154.187.243/?page_id=283&add-to-cart= <product ID> &quantity=1

Here's mine:
http://35.154.187.243/?page_id=283&add-to-cart=300&quantity=1

5. Now use the link we just created and add it to any button as a hyperlink