Yeah, but that's only if you set up a business where you unlock customer's phones for money. If you unlock your own cellphone so that you can use it on another network, that's not really for 'commercial advantage' or 'private financial gain', is it...?
You would need to delve into the case law to see how the court interprets the phrase "private financial gain" in the context of the statute. The language could be interpreted to mean that you did not buy a more expensive unlocked phone, but instead, to save money, you unlock a subsidized phone.
In fact, I don't know how else it could be interpreted. If you do it for a third party for money, that seems to be "commercial advantage". Doing it for yourself in order to save money seems to be personal financial gain. But my guess is only a guess.