We have a bulk tank and purchase ours from an outside oil company that we used before we got on the GM program. I think we pay $1.20 per gallon for -20* fluid. In the warmer months, you can stretch it out by cutting it with water.
I have even heard stories from the driver about some places that will buy blue toilet tablets and add to straight water in the summer months.
I called my local NAPA and we're going to switch to them when I buy my next batch of fluid. Going to be saving almost $35 per drum on premix.
We've had problems mixing our own from concentrate, and I do not have the space in my parts room here to mix it in-house. We keep it all in our lube bay next door.
WE GET IT FROM VESCO OIL. SUMMER 1.69 A GAL ,WINTER 1.79 A GAL . PARTS DEPT DOES NOT TOUCH IT. YAY. WE DO SELL THE 1051515 OPTIKLEEN TO EVERY PREP THOUGH.