My point was, the legitimate source Amazon is a registered reseller with the equipment manufacturer, and may include the valid traceable laboratory certificate with the item for a slightly higher fee.
Another problem with clones for example, is they often copy old tech... defects and all... so in this example one probably won't get the current inductive style absolute position verniers that work more reliably around dirt/liquids.
Just a thought, but note often 3rd party sellers are literally sourcing items from dumpsters. There was a news story about the disgusting food people resell on the platform, and it is not technically counterfeit. =3