I think for many people there is a clear line between free and not free, no matter whether the service costs 2$, 7$, or 100$. It's a psychological thing. On top of this, it could be 7$ now, 14$ next year, and over time you get sucked into this money pit.

A good example is Adobe products. Pre-cloud I would freely use PS/Lightroom off a CD, then got into the monthly plan for students, which turned into a full price plan after I graduated, and which sucked me into a year long contract for a certain plan.

Now I did this all willingly of course, and after 5 years I looked back and thought 'where did all that money go?' But to some degree it undermines my trust in my ability to gauge the actual value of subscription based services.