Ita, might want to check out this link. Another person with a similar question, answered by Todd of Lindeblad Pianos, with suggestions for places to offer it for sale. If you were to post a message to him through that site he may be able to give you
a reasonable estimate of value.
BTW, welcome! http://en.allexperts.com/q/Antique-Pianos-3969/2009/8/Stultz-Bauer-1903-Upright.htm