It's horrifyingly hard to convince people of this, though, even you can present them with actual numbers.
A lot of people have convinced themselves that cloud is cheap, to the point that they don't even do a cursory investigation.
A lot of those even don't do the bare minimum to reduce hosting costs within the cloud they choose, or choose one of the cheaper clouds (AWS is absolutely extortionate for anything that requires significant amount of outbound bandwith), or put caching/CDN's in front (you can trivially slash your AWS egress costs dramatically).
Most of my consultancy work is on driving cost efficiencies for cloud, and I can usually safely guarantee the fee will pay for itself within months because people don't fix even the most low hanging fruit.
A lot of people have convinced themselves that cloud is cheap, to the point that they don't even do a cursory investigation.
A lot of those even don't do the bare minimum to reduce hosting costs within the cloud they choose, or choose one of the cheaper clouds (AWS is absolutely extortionate for anything that requires significant amount of outbound bandwith), or put caching/CDN's in front (you can trivially slash your AWS egress costs dramatically).
Most of my consultancy work is on driving cost efficiencies for cloud, and I can usually safely guarantee the fee will pay for itself within months because people don't fix even the most low hanging fruit.