I can tell that these are fake SD cards at a glance - why can't amazon?
There are two exceptions (that don't apply here) to that rule that I can think of. They both aren't really exceptions, but rather weirdnesses in market value where it can be much lower than the market value it would've had in case of ideal information flow and in the limit of large market.
One is if a product has a new release every season, then old season's release (even if ~identical to the previous) is often deeply discounted. I think it's often caused by people thinking that there is more of a difference between them, which is to the producer's benefit, so they encourage such misconceptions.
The other one is where the market for a particular version is small: then the price of it will be much more volatile. For example, this happens to weird sizes of clothing.
