When I started buying online ads back in 2013, I wasted a lot of $$$ on simple mistakes that I could have avoided, if someone had told me to stay away from certain things. I just wish I would discover the STM Forum sooner, since all the most common mistakes were already documented inside the many threads that the other members started.
And that's how a paid forum can actually save you money… learn from the mistakes of others, benefit from the knowledge of those who made it!