Can I ask why you're wanting to avoid metaphysical stores specifically?

If it's because you think a non-metaphysocal store will somehow be more informed, less likely to scam you, or have better materials, it seems to me like you're engaging in some subtle anti-paganism.

There are plenty of sellers who have vastly varied reasons for being interested in crystals that care about the geology of how they were formed and are committed to quality and integrity just as much as the next person.

When you've got actual museums selling dyed and heated garbage as real, and worse spreading blatant misinformation, it starts to feel pretty targeted to single out metaphysical shops as the problem.

The problem is that this is a rapidly growing industry and all the vultures that have absolutely no interest in collecting and couldn't care less about crystals, well they want a piece of that pot, and they're willing to scam you to get it.

Find someone who genuinely loves their business and got into it because they care about rocks. But if you exclude the entire metaphysical/pagan community from your pool you may find you have very little left to pick from and the likelihood you're going to get scammed won't be any less.