Ah, didn't expect such a response! I'll try to hit all the questions.
My main reason for quitting is health reasons. I am borderline obese and about 1/2 of my calories daily come from soda. This would be 1-2 Mt. Dew's in the morning, maybe a Pepsi at lunch, and 1 Mt. Dew in the afternoon (all 12 oz. cans). At night it's 1-2 cans of Pepsi. I have terrible ebbs and flows in my energy levels, these are partially (not fully) connected with soda / sugar / caffeine. I am not diabetic but easily see becoming diabetic with current sugar intake.
Another reason is I am trying to ween (heh heh) myself off anything I am "dependent" on. This includes certain foods and some medications I am taking that are crutches.
Cost doesn't really play in to it, besides the fact that pre-packaged alternatives are more expensive. I tried Naked Juice Smoothies, and though "natural", they have a lot of sugar and are very expensive to use as a full replacement. I tried grape juice but somewhat expensive and still loads of sugar. I am going to look in to soda stream, I knew about it but never thought about using it for a "non-soda" drink.
I LOVE the taste of Pepsi.
Caffeine pills I think would only be reasonable if I was trying to break the habit of having a drink in my hand, and once that was done, tapering the caffeine pills. It bugs me to trade one form of the same drug for another but as with money problems, it's usually about everything but money so it may still be a solution.
Someone mentioned I should just stop and move on. I have tried that, but my job is mentally demanding and I can't sit there with a massive headache unable to string two thoughts together, so it has to be another method. I have quit maybe 3-4 times and have lasted anywhere from 2 days to a couple weeks, but that's it. I am trying to combine stopping soda with a new workout schedule so that the morning "wake-up" is handled by exercise and the afternoon lull is handled by some other method, sans soda.