I have found the "great value" brand of Distilled Water to work quite nicely for ALL my distilled water needs. It is also a fantastic value of 74 cents per gallon and also, it does not get taxed in my state due to it being a "food product," so can also be purchased with food stamps, designed not to help you starve, but hey, 0 calories is good for you.
I travel to the famed vendor "Walmart" to obtain it when I need it, and it's so cheap, I also keep a gallon in my car for my radiator/heat stroke needs. Probably overkill for both thirst and my radiator, neither of which require distilled water, but hey, it's like really really cheap.
Said distilled water goes into my DIY mixes at times, its performance there is unremarkably remarkable.
You can also make your own I'd bet for cheaper if you own a kettle and some items that you could probably cull from your shed or whatever should you so desire, to create a little at home condensation device.
There is however, then at that point, the cost of your time and labor versus getting someone else to do it for you, I value my time pretty low, but not low enough for THAT.
LOL
Anna