stuff you have proven works for you.
Creatine
This has not worked for me. I am a non-responder.
However, the reseach and anecdotal data from some of my lifting buddies has demonstrated Creatine is one of the best supplement.
Creatine also provide some health benefits.
Caffeine
For many individuals Caffeine enhances training.
Caffeine is in the majority of Energy Drinks. Caffeine produces around 80% of the "Energy Effects" for Energy Drinks.
The addition of additional ingredients assist. However, the remaining ingredients only increase the 20%.
The additional ingredience drive the cost up around 80%.
Thus, you end up paying more for the additional ingredients that don't do that much more.
Walmart Caffeine Tablets
The price for 80 Tablets is less than 4 cent is less for each tablet.
Rather than overspending for Energy Drinks or some type of Energy Tablets, purchase the Walmart Caffeine Tablets.
You'll get the same effects for a lot less.
Protein Powder
Research shows that Muscle Protein Synthesis is elicited with around 40 gram of protein per serving.
That is the amount of protein needed per meal to obtain enough Leucine.
Leucine is "The Anabolic Amino Acid". It turn on mTOR (Mammalian Target of Rapamycin); which trigger the anablic effect for building muscle mass.
Cost
1) Both Creatine and Caffeine are cheap.
2) Protein Power is moderately prices. The price of 24 gram of Protein Powder is around 50 cents or less, if you shop right.
Comparative Protein Cost
1) Milk
24 oz of milk provide 24 gram of protein. The cost for 24 oz of milk is approximately 56 cents.
2) Eggs
6 eggs provide 24 grams of protein. The cost, if you shop right, for 6 eggs is about 72 cents.