Hello!
Magento or any other Cms. It seems to me that is's an eternal question.
Let’s make a brief comparison:
· Shopify is a paid, while Magento is free to use.
· Magento requires your own hosting with following installation, setting up and configuration. It costs some efforts. Shopify is a hosted solution.
· As for inventory management please be aware that Shopify restricts the number of store items, while Magento has no such limits.
· Magento enables discount codes to create,Shopify doesn't provide such services to apply.
· Shopify offers 70 payment gateways, while Magento is considerably limited.
· Magento provides more themes for free than Shopify offers. By the way paid the themes’ price in Magento starts at $1.
I think there is no sence to continue this list further. I've emphasised just what I think essential. What other features may you enumerate usinf your own experience and preferances?