I just moved one of the largest (5+PB) data warehouses of Europe to AWS and we saved 35% of a huge (1M+ / year) budget while increased reliability, availability and security. I am not sure why people think that AWS is expensive. Running on a traditional hosting was a nightmare with constant downtimes because of issues outside of our control. Cooling, networking, security you name it. AWS makes these non-existent or very easy to tackle. For example of networking, there are several teams of network engineers oncall for AWS the handle routing issues etc. and you just get an email about it. With the previous vendor we found about the issue, tried to reach the vendor and we had to convince them that there is an issue and it took them 2 days to recover.

I am planning to move to AWS more entreprise clients for saving significant money on IT. AWS is most definitely a competitive option for this.