I don't really care so much about the cost savings. I care more that I'm doing the right thing in the long run and in control of what goes into my pool...I'm the one who buys mustard and mayo, then mixes them together when I want Dijon mustard, ya know? I am saving money this year for sure, and that to me is a side benefit. Truly, if it cost more and worked better, I wouldn't blink...
I only use bleach or pool chlorine, regardless of the trips to the recycle place, exclusively because Dichlor shock added CYA I didn't need and only added to my problem of overstabilization. Cal hypo shock bags added calcium which I already have enough of so once I discovered TFP I never looked back. And truly if shocking, even with Dichlor or cal hypo, was being done effectively the way it should be done all along to kill EVERYTHING, then yes the bleach is infinitely cheaper.
Most people think you throw in the shock bags and you're shocked. Not true. Even if you use the bags you still have to raise the FC it and keep it there until it's all dead.