While I agree premium aquatics is at the top of my list of preferred vendors. Privately owned by a fellow hobbyist much like BRS used to be and they are small enough that they aren't charging sales tax yet which can be a huge saving on big ticket items. Stock is very similar to BRS.Why you all shopping at BRS if price is a thing? They are nearly never the cheapest. Look around. You pay for all of those infomercials, points, giveaways, etc.
Check the sellers on Amazon and stuff. If they are in the US, then the product is probably fine... many are stores looking to offload product. Amazon will always accept a return for knock off stuff. SWA, Champion and many others offer stuff cheaper than BRS. If you want things like RO parts and supplies, you can buy many from the people who actually make them for a substantial discount... same with chemicals and media and stuff.
On things like this, why not check eBay or the local marketplace for use stuff. It isn't like the go bad. I have gotten Tunze Care on ebay for $20-30 and they work perfectly and make most other magnets look like childs toys.