You do realise that a buyer has the option to buy an item or not to buy an item.

And the same goes for a seller,  we have the option of listing an item for $10 or for $10,000,   Now if it is only worth $2,  than the buyer should be smart enough to buy the $10 one, and not the $10,000.

Not sure what your issue is.  The price is presented to the buyer, they don't have to hit the Buy it now button.

You seem to buy stamps and collectibles of that nature,  pricing is extremely subjective.  And as Sandy said an example are the $2 coins,  which again its not fraud,  its buyers not doing their homework.  And the seller trying to get the best price for an item.  I guess when you go into a car yard you pay the price listed on the car windscreen as well.