One gas canister：GBP 10 / 60L water

Per 330can = 0.055

Only Soda maker price: (+plastic bottle) = 39.99
（given 1個月消耗 24 can）13 個月回本



Cost for Pepsi max

Pepsi Max 6-pack £29.95
1 pack = 9L ~ GBP 5
6 pack x 9 = 54L
29.95/ 54L = 0.5546 
Per 330ml can = 0.183
soda + pepsi = 0.238 = 23p per can

Normal Pepsi Max
36p per can
savings for 24x = 8.72 - 5.712 = 3.008 


69.99
4支汽水 5x4= 20
Co2 = 10
兩個膠樽+ 部機 + Co2 按金= 39.99