$500 for a good one with a scope
Between 300.00 and 335.00
Between 50-75 dollars.
Your serial number indicates that your Marlin model 782 was made in the year 1977.
1985
1988
Your marlin model 782 was made by marlin in 1980.You can find this by subtracting the first 2 digits from 100.Hence 100-20=80(1980).
The Marlin 782 is out of production. Sale of used guns in good condition runs right around $200, plus or minus $50 based on condition.
Your serial number indicates that your model 782 rifle was made in the year 1981.
$250.00 to $300 isw hat a good one is worth!!
If I am reading the code table correctly, 1971
150$ to 250$ is my best guess
Try e-gunparts.com, local gun shop, local gun shows, etc..