Well, not everything works for everybody. Some people will prefer macOS over Windows, as they may find it easier to use, or more ergonomic, or feel that it is contains less bloat, requires less maintanence, is less prone to viruses, or is simply better. Other will prefer Windows, as they may find it runs more software, is more adequate for gaming, has better productivity apps, or is simply better overall. That is a matter of opinion, and it is not possible to put a price on it, so it does not lead to an objective discussion. How much Windows or macOS is worth to me is simply a subjective question, and destroys any attempt to compare similar systems. If macOS is considered better than Windows in every situation, then it is not possible to compare computers using these two operating systems, as they would be considered different products overall.
There are of course other factors to be taken into consideration. A Mac is more expensive than a Windows PC, but may have a better sale value. However, it is not possible to determine the resale price at the time of purchase, as it is not possible to know whether the computer will be lost, stolen, or broken before it is put to sale. If this is to be taken into account, then one should also consider the interest rate, or return on investment, on the price difference between a Windows PC and a Mac. Complicated equation.
One may also argue that a PC will require more maintanance than a Mac. That might be true, but it may also be true that Mac maintanance is more expensive. So, the probability of the Mac needing assistance may be offset by the cost of such assistance if and when required. Again, complicated equation.
It may also be argued that a Windows PC requires an anti-virus, which may increase the cost of the computer over the years. Well, an anti-virus may be required or not, depending on the user. There are free anti-virus software available. And of course each system and user will have different requirements. A Mac user, for instance, may have to buy a Windows license to run Windows software, while this will be already included in the cost of a Windows PC. Once again the equation is complicated and not simple.
It is also hard to determine which system will last longer. Microsoft and Apple keep updating their systems, and pushing specifications forward. It is not easy to know when the computer will become too slow to be used, or incompatible with new software.
So, the only objective measure here are the specifications of the computer. Which, again, is not that objective. A user may find that the Mac Mini or the iMac are more compact and will fit better in the room, so they may see more value in this. Power and heat management also tend to be quite good on the Mac. And that again deviates the equation.
On the other hand, the Mac is a closed system and must be bought "as is", with a few customizations to upgrade the processor or the memory or the storage. A PC can be built from the ground up. It may be possible to build a PC with the same specifications of a Mac Mini, but a user may have different needs. Perhaps the user does not need as many Thunderbolt ports, and want a better processor or a better video card, for instance. The PC is much more flexible. And, spec by spec, it is also a lot cheaper.
The only way to argue against that is use non-objective criteria and difficult, if not impossible, to precify: "macOS is much better than Windows", "Macs are designed better", "Macs have better resale value", "Windows will need anti-virus software that costs money", "Macs require less maintanance", and so on. All of this may or may not be true, and it is difficult to put a price on it. They may be good arguments in a PC vs. Mac debate. But the possibility of lower price is one of the advantages of the flexibility of a Windows PC. Should Apple allow macOS to be installed in any computer, it could be as cheap as a PC.
