The value as mentioned, depends on the condition of the gun and the grade. Look on GUnBroker and not just on the listed prices, check out the recently sold models that look like yours.
Of course I wouldn't sell my M37 for any price unless it was a "crazy high" price. And if yours was inherited, hopefully there will be some type of good sentimental memories of the person who willed it to you, every time you use it.
My advice if it's in good shape at all- have it reblued, and clean up or refinish the stock and use it for 50 years and will it to someone else.
Here's my favorite M37 20 gauge. And it's not for sale!