Not the first to say this but: Sodastream. I wanted glass bottles so I didn’t think a sodastream was possible for me but it turns out there is a glass bottle Sodastream and Lu can get it on sale for a bit above $100. I have bottles and haven’t spent a penny on Perrier since buying it. Plus I can take advantage of my fancy home water filter.
There are DiY videos for going the cheaper route and just buying a large CO2 canister that will last you a couple years and hook it up to the same device after buying a couple valves. It's on my project list after I finish my kitchen reno.
Not sure where you are but most big grocery stores will have them at the front or the meat department in a special bin. just ask for how much you want and they dish it out. i know ralphs/kroger/staterbrothers should have them.
Reference: https://helpatmyhome.com/which-sodastream-and-soda-makers-ha...