the following are only the Best Calipers I could find UNDER $50
these were the top 2
this is a JPEG rendering
this is a zip of the excel file
Best Calipers UNDER .zip
For near $100 Mitutoyo 500-196-30 Advanced Onsite Sensor (AOS) Absolute Scale Digital Caliper, 0 to 6"/0 to 150mm Measuring Range, 0.0005"/0.01mm Resolution, LCD With Certificate of Traceability to NIST 129.29
There are better ones -- Mitutoyo, L S Starrett Company, Brown & Sharpe, Fowler-Sylvac, BAKER, etc; some over $13,000