If you're deciding solely on cost just buy a bottle of caffeine pills from your pharmacy. A 100 count bottle of 200mg pure caffeine (well, plus cellulose or whatever holds the pill together) costs me like $20. Now do the math on 100 red bulls.
I mean, no one who buys energy drinks does it only for the caffeine. I'm just saying there's little difference between a redbull and a generic energy drink.
The relative prevalence and average amounts of the top ingredients were as follows: caffeine (100%; 174.4 ± 81.1 mg), vitamin B6 (72%; 366.9 ± 648.1 percent daily value (%DV)), vitamin B3 (67%; 121.44 ± 69.9% DV), vitamin B12 (67%; 5244.5 ± 10,474.6% DV), vitamin B5 (37.3%; 113.6 ± 76.6% DV), and taurine (37.3%; amounts undisclosed). Conclusions: Our findings suggest a high prevalence of caffeine and B-vitamins in these energy products, with many of the formulations containing well above the recommended daily value of B-vitamins.
Some are just alcoholics too. Alcohol reduces your ability to absorb Vitamin B, so they need to supplement it. If you pay attention you will notice heavy drinkers tend to consume a lot of beef, slam energy drinks or both.
None of the things you described are sodas, so I don't see how it's comparable. There's a difference between a cool drink and chocolate, it's not just a matter of taste.