The R/O Prices are a little lower than that and operation costs would be very low for a small grow. You could get the filters for 23 dollars and replace your membrane every two or three years for a small grower. But yes it is an upfront expense.
Exactly the reason to go with white. Some light leek will be no problem. The only major adverse reaction to light is algea. So if you start getting it worry then, Till then you made the right decision.
Also you are going to want to clean your gear like you never have before. and throw away all neoprene air stones and shit thats cheap to replace. then clean the fuck out of your cloner agiain.
They're is a good chance that your pump is overheating your solution. A cycle timer like an ART_DNE will fix. I have also seen some leaking thru the neoprene discs and with the clonex added it has built salt on the plants and made them mad that way.