If that works for you great. Seems like a gigantic expensive pain to me. .75 a gallon adds up.
It does add up but the initial investment on an RODI system is also not cheap either. Figure the following:
$150 RODI system
$10-$15 misc hookup for a standard faucet
$40 for a pair of garbage cans on rollers (one for pre-mix/one for RODI if you want to have a bunch of water ready to go)
$40 for the cost of something like Instant Ocean Salt (makes 200lbs)
$40 for the cost of a pair of tank heaters to keep the pre-mix/RODI water at temp
Periodic Replacements of the Resins
Cost of a couple of siphon pumps ($40-$50)
Have tubes going every which way and either finding a use for or disposing of 3 to 4 gallons of wastewater for every good gallon of RODI water that you get.
Need to make sure the salt is mixed well in advance
Conversely the buying method involves the following in the case of the guy with the 14 gallon tank:
Buy (4) 5 gallon jugs (3 for the tank and one for RODI top off) at between $6-$7 a piece for ones that have caps and handles for easy transport
Drive to the store and Buy premix at 75 cents to a dollar per gallon.
Bring water to temp
Buy an $8-$13 simple manual siphon hose and place the jug up higher than the tank and let it drain in or simply hold the jug up and pour it in the tank and eliminate that cost
I guess I just fail to see where the hassle factor is so much more in that situation and it is going to take a couple of years to recover the cost vs simply buying it.