A LFS do not look for keeping coral long term. Their practices are not exactly something inwoild recommend to a home aquarium.. my 2 cents
It was a mildly amusing story in reference to a post above about bringing home 30-40 gallons of water at a time seeming like a lot. No more, no less.
While this particular store didn't do a great job in their store, the individual referenced above kept his 210 as an SPS tank that was the envy of everyone in the local reefing community who had the privilege of seeing it. If he was still living I'd ask him for a picture. Who are we to say he was doing things wrong?
I'm aware that people with larger tanks who do water changes and know how to balance a budget typically choose to make their own water and salt. I do this, and the OP seems to as well. I'm not trying to dissuade them.
If you want something directly on topic:
You may find that a lot of the price differences between salts balance back out when you discover that they tend to rate their volume mixed at different salinities, so take that into account.
I happen to use Red Sea Coral Pro because at the time I was running a higher alk tank and servicing lower alk tanks that used water changes as their replenishment method. I also like to keep my Mg higher than most salt mixes come in at. Once I did the math on cost per volume corrected to the same salinity it wasn't really any different in price than using Reef Crystals. At the time I picked a salt (years ago) Fritz had recently shipped a bad batch of salt to the LFS which caused a pile of problems. Knowing that Red Sea would provide a per batch lab report, I decided that was a better risk. I know several people who use Fritz and have never had an issue, so I don't mean to single them out.
My short form advice on salt is: Pick the alk you want, normalize price to a constant salinity, and either stop there because it really doesn't matter much past that, or go with your personal preference and recognize that it's a bit like religious preference at that point.