How do I avoid counterfeit Mitutoyo calipers on Amazon?

This is a documented problem, r/Tools and r/Machinists threads (including a counterfeit 500-196-30 post) repeatedly warn that fakes are widespread on Amazon and eBay. Reviewers advise buying from authorized industrial dealers, checking print quality on the back label and QR code, and being skeptical of prices well below the typical $120–$150 street price for a 6-inch Digimatic.