The question can't be answered without knowing the caliber, number of shots and all markings.
50-100 USD
Impossible to answer because you did provide any information about the revolver or the serial number.
a serial number for a model 29 sw is 72-486
1977
The serial number.
Call S&W and they will tell you.
100-400 USD
50-350 usd
1973 or so
You will have to call S&W to find out.
You need to provide the model number and serial number. If it was made before 57 or so it will only have a serial number. Also, provide the markings on the barrel, frame, etc.
100-300 USD