I posted a question earlier about creating shopping cart from scratch(they've closed the question) but i think i must reframe the question because i left something important in the question.
I know shopping carts like "Magento Community Edition(very big software)", "OpenCart", "Prestashop", etc, are opensource and maybe huge to develop by one programmer.
What about hosted shopping carts like "shopify", "BigCommerce", "3dCart", etc.. are these carts too huge for a one programmer to develop them within 0-2yrs?
Are there huge differences between the opensource carts and the hosted carts?
Thanks for your answer.