Great post, especially on the section of shopping carts - nice to see how you went through trying to figure out if you should go SaaS vs hosting a cart vs creating your own. With that being said, I think another solution that people may want to consider if they go the SaaS route and are looking for an easy-to-use shopping cart that's scalable is BigCommerce (https://bigcommerce.com). As they're a SaaS solution, they also take care of security, charge monthly subscription that can be upgraded/downgraded as your business needs, and have a good amount of apps.