I paid $2.67 per box at Walmart.
Prior to adding the borax, I was having to add 5-6 lbs of cal-hypo or more per day and keeping the fc above 20 ppm. 2 days now, I added 1 bottle of bleach to keep fc above 6 ppm, my cya is still close to 50.
I'm having trouble letting go of continuously adding chlorine, it's become a habit.