Hm... At $3.99 for a 12-pack, it costs you about 0.33 a can for a name brand soda. Sodastream's website says it costs you about 25 cents a can for a savings of about 8 cents a can. With an initial investment of $200, you would need to drink 2,500 cans of soda to break even. That's the equivalent of 208 12-packs of…