Protein, creatine, fish oil and multivitamin are the only supplements needed (nitric oxide is useful as well if you lift hardcore). All the other stuff added (glutamine, bcaas, so on so forth) do not give enough gains for an average gym goer to have the need to take spend money on using them. If you are sponsored and get them free it's a different story. Places with the best prices on the useful ones I have found are vitaminshop.com (they do a lot of discount codes and stuff in emails) bodybuilding.com supplementwarehouse.com and amazon.com