Welcome... you have a nice original early SA dagger by a fairly common maker with a correct early hanger. Gau marked BO for Bayerische Ostmark which you stated. Generally an early SA dagger exhibits better quality, is more collectible and hence has more value; however this also depends on the condition of the dagger. The price of SAs has been lethargic of late and I'd put the value of this piece with the hanger between $575-$675 IMO.

Last edited by Fitzer; 08/28/2013 04:41 AM.