I own a Eagle eye pinpointer, and would not recommend it.....
It will barely detect the edge of the coin, when touching it.
I'd say go for the harbour freight pinpointer, tune it, as they do on the youtube videos, and save up for a Garrett propointer.
The Eagle eye will detect the flat side of a coin on a distance of about 1 cm....
I spend most of my dirthunting breaking up dirt and running it over my coil..
HH.
/Steffen