Firstly I am not a dealer nor do I hold any franchises.
However I have seen a lot of potentially dangerous sold on Amazon & Evil Bay
Things like a stack of blades that were plain carbon steel and wore out in no time flat.
Even more dangerous some that were high carbon steel ( lke cheap taps & dies ) that shattered when they hit a tree root and is one case a blade that was not centered.
And then there were the blades that were 1/16" shorter so after a single season left a Mowhalk between the blades.
Carbs that had no main jet, carbs where the venturi tube was not drilled out.
Then belts everything from pollymere belts in a kevlar sleeve belts at the wrong angle , belts wrapped in toilet paper thin covers , wrong angles and wrong lengths .
As for bearings anyone who buys bearings from Amazon or ebay deserves what they get which is usually a bearing that has at least 1 less ball than a proper one, made from substandard materials & even machined rather than being ground & polished