At Leslie's, the Genesis Shock shown
here is about $20 for a 6-pack with each pack being 10 ounces, but since only 67% pure this is equivalent to 6.7 ounces of normal Trichlor pucks. So that's $20/(6*6.7) = 50 cents per ounce of pure Trichlor. Even the more economical 36-pack is $107.64/(36*6.7) =
45 cents per ounce.
20 pounds of pure Trichlor pucks shown
here at Leslie's is $60 so that is $60/(16*20) =
19 cents per ounce of pure Trichlor.
The nearly pure Dichlor shown
here from Leslie's is $31.19 for 8 pounds. This is equivalent in FC content to 77-1/2 ounces of pure Trichlor so is $31.19/77.5 =
40 cents per ounce of equivalent pure Trichlor. However, if you want to look at the price comparing what you get in CYA instead of FC since that's why you are really buying the product, then 8 pounds of Dichlor is equivalent to 116 ounces of Trichlor so the cost would be $31.19/116 =
27 cents per ounce.
Basically, the Genesis Shock is a rip-off. If you wanted to easily add CYA to your pool, the least expensive approach is to use pure CYA, but if you wanted to just use a chlorine source to add to CYA, then Trichlor pucks would be the next best and then Dichlor after that.
Richard