I figured I'd move this post to an open discussion, as it is a good question. The breakdown of costs is in the
server treasury topic. Our forum hosting is about 85 dollars a month. Cheaper hosting can't handle the size and use our forum has, unfortunately.
The game server accounts for a little under $150 a month. I will preface this with that I am not by any means claiming that we have the best solution, or that I am the most knowledgeable in the topic.
I've looked at the provider you've linked. They provide cloud servers for very specific games. Those games are generally easier to run, as well as being run on cloud infrastructure. That means that they require less resources, and cloud hosting can often be cheaper, since you can easier run more servers on the same cloud server, hence divided costs. I was unable to see how many people such a server could host, and how pricing scales, since they do not seem to offer NWN2 hosting.
That is also part of the issue. I've yet to find a way to host an NWN server on anything else than a windows server. Windows servers unfortunately are more pricey, since you have to buy or rent a license as well, and you need to rent something that can run the entire windows OS, instead of just the game server software.
As far as I know, the biggest issue is the older software, which means it just can't easily make use of newer (and cheaper/stronger) technologies to host a game server. I've tried, but have been unsuccesfull so far.
But, if people smarter than me have a better solution, then we're of course all ears!
