Brooksy,
what results are you looking for with Powerfull? If your expectations are realistic, I'd bet that just buying a bottle would be worth it.
In my experience, it's great for sleep quality but did not help me fall asleep. It was a good mood enhancer and it also helped reduce prolactin symptoms from a cycle at one point for me.
Some people like to stack it with a stim for a preworkout combo, but I personally don't like to do that myself.