Average $200-$300. Spelled Sturm BTW.
There is no such model number assocaited with the Ruger Bearcat. Do you mean the serial number is 918?
0-300 USD depending on condition.
200 or so
ruger bearcat 22 blue and brass serial # 62155
Impossible to answer without a DETAILED description of ALL markings, barrel length, finish, overall condition, box, papers, accessories.
50-200 or so
Ruger's website has sn data you can look up.
50-200 or so
50-500 USD depending on specifics
50-300 USD depending on condition.
50-200 or so
500 or so