Assuming you mean a Sterling mdl 287 PPL in cal. .380, these retailed new for about $90.
Best left to a gunsmith
50 or so
75-250 USD or so depending on specifics
We need the model- there is more than 1 Browning .380 pistol.
Make, model, condition. We need all 3 factors.
Impossible to value without a detailed description.
0-1000 usd
0 To 400.00
50-150 USD or so
gunshop, gunshow, gunpartscorp website.
Ask a gunsmith for help