I can't find the right group so the two groups this is being sent to are
actually each half-way related to the question below.

I made a home-built C02 carbonation machine using a 20 pound carbon
dioxide tank and some pneumatic hoses & couplings, which, along with a
tire valve inserted into a soda-bottle cap, allows me to easily carbonate
water at home, three liters at a time (as shown in this photo below):
http://www1.picturepush.com/photo/a/...g/12065184.jpg

My question is related to that machine, but it's related more to the food
flavoring - in that the entire endeavor is a waste unless/until I can
find an economical alternative to the desired cola flavoring.

Here is a picture of the cola flavoring I'm currently using:
http://www3.picturepush.com/photo/a/...0/12065186.jpg

The 'problem' is that it cost me $5 for the cola syrup, which makes 12
liters, or, roughly about 50 cents a liter. Compared to the C02 which
costs perhaps a penny or two per liter, and the water which is also
something on the order of a penny a liter, the whole home soda machine
project is a failure unless I can get the cola flavoring costs down.

Any ideas on how to relatively closely duplicate the cola flavor at a
substantially reduced cost than what I'm currently paying?