I made calls today to every pool store that came up in google maps in Wilmington, NC. Almost $8 - $10 across the board for 1 gallon of 12.5% (yikes)!
KMart has a 3 for $8 on 8.25%. That's the best I've found here.
Called an industrial supplier. They had 5 gallons of 15% for $40. Not that...