They should really make it obvious if it's commingled or not. I've read that some brands can block third parties and some 3rd party sellers can pay Amazon extra to stop their inventory from mixing, which seems like a scam on Amazon's part.

That only admits that the product receive may not be the same if it came from third party instead of Amazon directly.

When I want to buy something, especially low cost items, I don't want to spend time figuring out if something is commingled or not.

Whichever vendor offers me time savings in exchange for good quality products will get my business. Amazon no longer qualifies for that.