When I believed i was doing this, I was spending 12 to 15 hours everyday doing the shipping, labeling, answering customer queries, support, listing new items, negotiating with suppliers etc.
Although There we were dealing with only one product - indicates everything was easy to cope with. https://online-learning-initiative.org/wiki/index.php/Home_Based_Ecommerce_Business_-_Ways_To_Dropship_On_Salehoo