[Spooky23]

In my mind, it's like leasing a car. Leasing is better for your cash flow, but buying is usually a lower total cost.

Outside of large volume S3, it's pretty trivial to beat AWS costs, assuming you have the human capability. S3 is a little different, as the capital investment required to host petabytes of data is very high, and Amazon's economy of scale is pretty compelling.

For most anything else, dedicated boxes at a colo or your own datacenter should be cheaper, assuming you have the people around to do it, etc