FWIW -
Menard's seems to always have good pricing and stock on pool salt (might need next spring after rain/snow refill the pool) - I needed 4 bags this year.
Menards is convenient for liquid chlorine - but check date codes. Might need for early spring cold water use, or very late fall when water temps cause the SWCG to stop working. But no need for a personal stock outside of those times. The exception may be buying a large amount if pool is green when uncovering in the spring, OR you really, really let it get away from you over the summer.
Menards again for the Muriatic Acid - a gallon at a time is fine.
Costco (or probably Sam's or Walmart) for big bags of baking soda, IF needed. But again, no need to buy unless testing says otherwise.
CYA we've covered.
That's all that likely is ever needed.
After decades of $3-600 in chems each year (tabs, algaecides, clarifiers, flocs, etc). I'm shocked at how little I'm spending AND how little time the pool needs, now that I have the SWCG and a great filter.