This is a copy of a famous pattern crown (a non-issued prototype of a crown). Our picture contains three examples, noted A, B and C.
The A piece is a recent reproduction worth a few US dollars.
The B piece is also a reproduction, but its quality causes it to be worth more, about $150.
The C piece is an original pattern crown, slabbed by NGC. It is very valuable. It sold for $14000 in a 2019 auction. The patterns in the C piece are incuse, that is, they penetrate beneath the surface of the coin, rather than normal patterns which protrude above the surface.
I believe you have the A coin.