True, but due to the large extent of the services provided/required, it's very hard to know the unexpected costs, even if one has experience.
For example, one will hardly think of the cost of the disk speed (IOPS, in AWS), before moving to AWS. Then, they will suddenly have to deal with it (note that IOPS will be mostly opportunity costs, in case one doesn't choose provisioned IOPS of larger capacity).
The cheapest provider in existence runs on renewables (Hetzner Online). There isn't too much of a difference, especially for EU datacenters as they have a high excess of renewables and the energy market works in a way where you pay for renewables but just as everyone else you'll be using the base capacity generating dirty sources.
The price charts are all publicly available. Anyone can check for themselves what the costs are.