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So far, all I have ever bought with Bitcoin are precious metals.
The below companies are "in this space". I put a comment where I know something. Please feel free to add your experiences!
providentmetals.com fast service, good selection, offers related & other products, big company
amagimetals.com good selection, somewhat slow service
veldtgold.com fast service, interesting stock
coinabul.com not recommended, ensnared in lawsuits...
tulving.com was a famed seller of precious metals in LARGE QUANTITIES. They are now closed and under investigation...