Originally Posted by david_42
Less expensive RO units are not for 'realtime' usage. The one I had in Las Vegas was good for about 20 gallons a day. Looks like you can get a 3-stage 50 GPD system for ~$250. I paid much more for less, but that was 19 years ago.
75GPD is about the standard, and you can find good units for $150. Cheap units for under $80.
RO/DI, for all intents and purposes is about the same as distilled (from the store). Not semiconductor grade (unless you buy a good RODI unit), but better than we need.