I am afraid that this coin is almost certainly
fake.
It is a Tai Ping Tian Guo, value 5
type. However, if you look at the illustrations in Hartill's
Cast Chinese Coins, and the images on
zeno.ru you will see that the calligraphy is off. Especially the dot under the Tai (a line on your example, which is not correct), the Tian and the
rim thickness. The closest coin to yours on
zeno.ru is a
fake.
A genuine coin would be
scarce and should be worth over $100.
SC