FWIW, you can buy a sodastream unit for ~$70 and then for another $200 to $300 get a conversion kit and a large co2 cylinder and from then on the cost of carbonation works out to less than three cents per liter. Not sure what the syrup cost is since I only use mine for sparkling water.

I just wanted to comment to say that that is a brilliant idea. I only use my Soda Stream for sparking water as well, but I pay about 25 cents per liter for the standard refills.

I have a co2doctor[0,1] kit, a 20lb capacity tank from amazon (bought new - you can get them used but then you don't know where they've been or how clean they are...) and filled it for about $30 at Carbonic Service[2] in Santa Clara.

0. http://co2doctor.com/ (site down at the time this comment was posted)

1. http://www.ebay.com/sch/co2doctor/m.html?_nkw=&_armrs=1&_ipg...

2. http://www.yelp.com/biz/carbonic-service-santa-clara

Or skip the sodastream and special kit and buy a "carbonator cap" for 15 bucks. That, a tank, a fitting, and a regulator and you're good to go.

Helps that sodastream doesn't try to chill the drink, which you can just do ahead of time by refrigerating the water

I like Soda Stream and own one, but the syrups aren't very good if you ask me. I'd happily pay more for Syrup if it was the branded stuff that tastes right.

Part of the reason why, I suspect, is because they aren't aiming for 1:1 parity, they want "healthier" so they can put it on a billboard. Ultimately result is that they taste like diet drinks (only with more sugar).

I agree. I have one, and about the only want I can tolerate is their Cola Zero. However, I've since went back to Coke Zero cans, and was excited by the Kold, but the price really is a non-starter.