Heraia, Arkadia, AR hemidrachm, 2.65 g, ca 470 BC. 

Head of Hera right, wearing stephane and earring, hair in a
queue behind her head.
ERA, a dotted line above and below, all within incuse square. 

BMC 10; BCD Peloponnesos 1355 (this coin); Traite I, 1221;
Rhousopolos Coll. 2805.

with permission of cngcoins.com, Triton XIII, Jan. 2010.
Extremely rare.
Estimate: $7,500 USD