I've been looking at cranks on ebay and noticed lots of cranks that look like copies of Shimano.



$15.12 shipped:

https://www.ebay.com/itm/MTB-Bike-Cr..._jw:rk:28:pf:0

A shady operator could order those unbranded, slap some Shimano (Altus or Acera) stickers on them, then sell them for triple that price. People looking for lower end parts might be less likely to spot fakes than those looking for higher end parts.