Book value is $15 in F, $35 in VF, $50 in XF and $80 in UNC. Realistically I'd say you'd get $15-$25 no matter the condition. I love these coins, by the way. I have a large Portuguese collection and I still need some from this era.
Very cool Portuguese coin ... congrats!! Ummm, I don't have any Portuguese coins, but I do have this sweet ol' Portuguese paper-note => 1000 escudo (from 1942) ... => Oh, and I married a hot Portuguese girl ... does that count?