You have only provided a generic description and no such model number exists. Thinnking you misread the model number, trying to put a value on anything with just this limited information provided is difficult. Value depends on a combination of many factors. Without a detailed description to include, finish, barrel length, overall condition, stock material, sights, box, original paperwork and any accessories, only a general estimate can be given. This weapon could be in the 100-550 USD price range.
100-345 USD
100-450 USD
100-435 USD
100-500 or so
500 maybe
50-450 usd
50-500 usd
400 or so
No way to value with just the serial number.
Derringer 2 Shot, 357 Mag, SN 929, what is the value
model 15 is not made in 357 it could be a19-3
Model 15