At least those prices from your link aren't as high as what people regularly spend for fake '52 T and '51 B Mantles.
Listings like this irk me a lot more, because it's from a dealer with a lot of (100%) feedback, and he goes to great lengths to divert attention from authenticity with nothing but supposed trimming talk and "evidence".
It's not even a good fake. Standard red flags for this card (like Mantle's bad sunburn and the wrong color under his cap's brim) are obvious even from those poor photos.
Swindling someone into paying $1500 for it
https://www.ebay.com/itm/Mickey-Mant...-/293804811035