I just bought one for 70$. Light surface rust, cleaned off easy.
They sell new for $125.00.
Get help from a gunsmith
50-125 USD
The value of a Topper model 158 12 gauge would depend on a couple different things. The main thing to consider would be the condition.
Depends on what it is choked.
Typically a used topper will run between $50 and $150 depending on condition.
you can buy parts for this gun at www.e-gunparts.com
100 max
50-150 USD
$50-$125, depending on condition.
$100
100 USD give or take