Things have changed a lot in the past nine years. Nine years ago, the iPhone was released. This was the first smartphone that got a lot of consumer attention, and it has changed everything. A year later, Android was officially released. In 2013, MacOS became entirely free for all users, although you must purchase an Apple computer that comes with the OS installed to begin with. Finally, last year, Microsoft released Windows 10 as a free upgrade from Windows 7 or higher (for a limited time), with the promise of free updates forever. Linux, of course, has always been free to install, and most Unix variants are never likely to be free. There are, of course, various other Operating Systems (OS), including BSD, Windows Phone (now merged with Windows), Blackberry OS, Chrome OS, and others, but Linux, Windows, MacOS, iOS, and Android make up the majority of what most people encounter.
So how do all of these affect the average person? Well, because the vast majority of people will only ever use the OS installed on their system when they purchase it, it means that the OS is largely free. Obviously they are not all actually free, but the consumer doesn't see what part of the cost of an Apple computer goes to the OS division and what part goes to the hardware division. They don't see what the manufacturer paid Microsoft in order to preload it with Windows. They don't see any of that, so it doesn't really matter. People only see how much it costs to upgrade, and what works or doesn't work. They really don't see the Total Cost of Ownership (TCO), or even really know what that means. So what does it mean?
Well, the purpose of the OS is to run your computer. Ideally it should start up as quickly as possible, start your programs easily, connect your peripherals effectively, and generally stay out of your way. The less you even think of it, the better. Every time you notice your OS because it is slowing you down, that increases your TCO. Every time you need to fix something with how the OS is working, that increases the TCO. Every time you need to replace hardware because it is no longer compatible, that increases your TCO. So what OS gives the lowest TCO?
It depends, of course, on what you are using it for. For the average home user, there is going to be a higher TCO if you have to install or reinstall your OS. For some businesses, that may lower it or not be relevant, because everything is installed from a single consistent image that is copied to each computer. If you need to upgrade your computer more frequently because your OS needs more resources, that is going to increase your TCO. On the other hand, if you can virtualise everything to a central server and have thin clients connecting in, that can reduce TCO as well. Of course, if your software won't run on a given OS, than trying to work around that is going to hit the TCO as well.
In most cases, once the system is set up and configured, if done properly, the ongoing TCO should be small, and limited to user training, update glitches, and hardware updates. The trick is to minimise the cost when you must upgrade, and limit the amount of user training that is necessary. As for update glitches, those should be caught before the update is general, by testing updates in advance of them occurring for the end users.
So what will your cost be for a system? It depends on what you use it for, but don't forget the costs down the line, from when you get it to when you replace it.
