The problem isn't usually charging for something, it's when the price model changes in a fundamental way. Especially when the pricing model scales in a way that

The problem isn't usually charging for something, it's when the price model changes in a fundamental way. Especially when the pricing model scales in a way that is very expensive for some subset of users. Pricing models contain assumptions about how people use the software, you can easily get priced out if you use it in a bit of a different way than usual. If you have all the information about the pricing model up front you can make good decisions about using the software or not. If the pricing model changes your decisions can get invalidates and might require serious effort to remove the dependency on that piece of software.