VitaCost prices are unbeatable, even after international shipping and customs costs, and you'll find products not available locally like Lion's Mane and high potency Bacopa. Highly recommended.
I've used Piracetam, PS, CDP-choline, Bacopa, Lion's mane, ALCAR, ALA in various combinations and trials for months. PS and Bacopa are the cleanest with no negative side effects. The rest of the stuff have side effects, like splitting headaches, especially Piracetam. You pay the price for any benefits gained from risky supplements like those, and the benefits in my experience were not substantial.
Really want a bang for buck cognitive enhancement? Olive oil. A couple tbsp of olive oil a day eaten on whatever, like a salad or something. Man. It knocks any $100 cognitive supplement out of the park, easily.
Not necessarily due to pure cognitive enhancement, but because of the overall feeling of well-being, which makes it easier to focus, be attentive and patient. Contrast that to the use of Piracetam, which makes you somewhat mentally hyperactive and fidgety, and then you have irritation and crash afterward. In my experience the longevity of mental performance is more valuable and effective than short bursts of performance at the cost of reduced quality of life.
The olive oil acts very much in the same way as Ibuprofin (pain relief medicine), but it's super healthy. Want to know what it feels like to have your brain lubricated? Olive oil. It literally feels like your brain is floating and soaking in a lovely oiliness, it feels so healthy.
And cardiovascular exercise. I do 10 minutes total of star jumps a week, and it suffices for now.