The value of your SAA will vary depending on its vintage, in addition to its model, caliber and condition. There are there generations of SAA, so I suggest looking up the generation of yours by the serial number.
Also, for the best valuation of your SAA, vice a ball park amount, contact your insurance company and ask them to recommend someone to perform an insurance valuation, and pay for this service. This way you will get an honest evaluation of your SAA without the worry of getting scammed.
I hope this helps.
The best handgun for self defense, is the one you have with you.