Strosniders (Ace) in Potomac, MD also has an ad that says HTH Liquid Chlorinator at 10% for 2.99. I went yesterday and it didn't scan at sale price, but the lady gave it to me when I showed her the ad online.
Link:
HTH Liquid Chlorinator (11182) - Pool Chemicals - Ace Hardware
Ad:
Stronsniders Hardware Store. Whats On Sale
Link:
HTH Liquid Chlorinator (11182) - Pool Chemicals - Ace Hardware
Ad:
Stronsniders Hardware Store. Whats On Sale