I was about to write back that we are not far off the advances to make these affordable and then did a google search and found that you can get a distilled unit on Amazon for $180 that is capable of making a gallon in 5 hours for about $.45 worth of electricity. That is far less than what it costs to buy distilled water at the store, which is around $1 a gallon. If you look at this from a break-even analysis, you technically start to reap the rewards of ownership after about 800 uses since the first 400 uses basically cost you $1.45 per gallon, then the next 400 costs you $.45 per gallon, but you are recouping that extra cost over the $1 retail price, so by the 800th use, you are getting water at less than half the price of the store.
I shave DE and this is an amazing idea. I currently use a sharps container, but this is so much more fun.