To get the radio at $39.95 you would probably have to sue and I'm not
sure you would win. I'm no lawyer, but I have to wonder if there isn't
some common sense rule that applies in situations like this. If it is
obvious to all that an honest mistake was made and the seller has
offered to make you whole (refunding all purchase costs) then you would
be in a position of having to show that you have been damaged by not
being able to buy the radio.