I've been using the
SodaStream now for a couple of weeks, and I've had a lot of fun, I can't speak about the cost yet, but the
SodaStream website says that it costs about $0.20 USD for a liter of carbonated water (then you add flavoring), I won't buy the
SodaStream flavorings because they are made with some bizarre artificial sweetener (but not Aspertame, they are very proud of that). I'd rather just use pure cane sugar, I honestly feel that it is healthier. Today I made a Key Lime

syrup (1 key lime and a about 1/2 cup sugar per liter---I made syrup for 6 liters using 6 key limes and 3 cups sugar), I've use Norwegian "Saft"

raspberry, was amazing (in England they call the concentrated drink syrups "Squash"

--I guess to imply squashed fruit with sugar), I've made my own energy drink using one of those little bottles of "5-hour Energy"

and some flavored syrup, I've made Italian sodas with carbonated water, syrup (Eggnog

, Amaretto

, Island Rum

) and sometimes a little cream. I've carbonated Kool-Aid (Kool-Aid makes a pineapple-coconut-ish one

that I added some cream to and it was VERY good) Watermelon-Kiwi

, Raspberry

, there are other flavors that I'm sure I will try as well. Anyway, if you want to try the
SodaStream as well, you can for just $19.95, see the website:
http://www.getsodastream.com/