1937 Three Pence Someone Said It Was Rare?

This was the first year that the 12-sided brass threepenny bit was issued for circulation, and they are very common. In this condition it's the sort of coin that most British dealers would chuck in their 'junk trays' where you can buy coins for 10p or so each.

There IS a very rare variety of 1937 threepence, but it has the portrait of King Edward VIII instead of King George VI. Most were melted down after Edward VIII abdicated, but a few are known to exist.