This is only true, if you do not value your free time. In your example, you've spent 4h to save 200$, so your work was worth 50$/hour. A freelancer with a 100$/hour rate might do 2 hours of work instead, spend the money, and gain 2 hours of free time.
There are other factors of course, but in general, many people come up with a rate for their own free time (which is often higher than the actual rate they charge clients)