The whole nootropic scene can get very expensive. Especially consider the ammount of experimenting one needs to do. Effects of any ingrediant can be extremly varying in individuals, and usually many need to be stacked. This has severley limited my research, even with a big interest in this area. I've tried: Piracetam, Nootpept, and a few Choline sources, and havent been extremy impressed. Nootpept definetely has an effect, and the only one Im working around now. I've also tried variois adaptogens.
The pre-stacked/formulated products are very enticing, because they can cut down on price and remove some of the guess work. However, I haven't made the jump to one because I have yet to see a formula that really impresses/overwhelms me. That said, I am on the preorder for Evomuse's Clear Edge, with very high hopes. Probably the best, most creative,comprehensive formula I've seen yet, and the companies reputation speaks for itself. I would definetely keep any eye out forblogs and reviews for this when it drops
To answer your question: I think they can be effective, but extremely hard to master. You rarely see someome with a consistant or permanent Nootropic plan. They seem to always be changing with dissatisfaction. If you decide to travel this road be ready to dedicate a good ammount of time to research, and investing a bit of cash.
Good luck, the pleasure just might be worth the pain.