I've noticed a few things here over time. One is that for some reason, liquid chlorine seems to be a LOT cheaper in the north and even the northeast, than in the south--at least metro Houston where I live. Two things have affected price and availability everywhere, though. People all over here (Houston area) have gone pool crazy. My little neighborhood of 50 homes has five pools under construction right now, and before the pandemic there were only five, so the number of pools here has doubled since the pandemic.
I bought liquid 12.5% at Leslies for $16 for four gallons last year--pre pandemic. By April it was $17. By September $20. At that point 10% at Walmart for 3.74 per gallon became a better deal, and that's still where it was on Monday this week in Katy, TX Walmart. As to the increasing prices, Walmart hasn't changed. Leslie's got greedy and they lost a customer. They weren't getting rich selling me chlorine and muriatic acid anyway, but now they don't even have me visiting their store, where I could buy something else, too.
It would not surprise me to see all pool-related stuff increase in price. My neighbor who signed a contract in December still doesn't have a finished pool. In fact, none of the five new pools here are finished. When our water feature pump cracked in the Texas freeze, it looked like we might be June before that could be replaced. We did find one, though. Increased demand is bound to affect all things connected with pools, although I suspect most new pool owners will be buying pucks, as that is the routine it seems in this area.
Another thing that's going to affect chlorine is just general inflation. Been to the supermarket lately? Price of avocados up from 59 cents to 69 cents? Price of milk? Eggs? Cereal? While not a scientific comparison, my grocery tabs are easily 10% more than a year ago. The U.S. money supply has in the last 10 months had 6 trillion dollars added to it with nothing--no goods or services provided in return. Less than that caused ten years of inflation from 1970 to 1980. I can think of no reason that won't happen again. If you can find an installer with inventory, this could be the time to get a SWCG installed, as it might be 20% more this time next year. I've shopped them a couple times. Once, the price was too high. Two others recommended against installing one (yes, they turned down business!!!) Maybe I'll call again.