Storing on your own hardware will always be cheaper (Backblaze has a great blog post on explaining why they built out their own data storage nodes at rented colo space because of this).
https://www.backblaze.com/blog/petabytes-on-a-budget-how-to-...
https://www.backblaze.com/blog/wp-content/uploads/2009/08/co... (Cost of a Petabyte by service vs DIY)