In your example above (needing it every 3 months) it would take over 5 years to reach that point.
I'm going to guess that within those 5 years it's likely that the developer would have released a new major release (with a new trial period), or that you would have reinstalled your OS (resetting the trial timer), or that you would have gotten a new computer...
> In your example above (needing it every 3 months) it would take over 5 years to reach that point.
That wasn't my example. It was 3 months between the first and second times.
In my experience, your need for a tool often increases gradually. You have a one-off project that needs a tool briefly, then a couple of projects a few months later you need to try it more, then it becomes a regular thing.
It's pretty rare that I go from never needing a tool to needing it constantly as an instant switch. Which is the only scenario where 7/14/30-day trials make sense.
In your example above (needing it every 3 months) it would take over 5 years to reach that point.
I'm going to guess that within those 5 years it's likely that the developer would have released a new major release (with a new trial period), or that you would have reinstalled your OS (resetting the trial timer), or that you would have gotten a new computer...
In other words, you'd never pay for the software.