No more than 50 USD if new in the box.
15-50 USD or so
Sauer, Schmidt, Rohm
While the value of any firearm depends on its condition, the RG revolvers were very inexpensive firearms when new, and are typically worth $50-75 US.
Inexpensive and fair to poor quality.
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Not worth more than 50 USD
No sn data
Could be Sauer, Schmidt, Rohm, RG, Gecado, or any of a dozen others.
The Dickson Commander appears to be the same basic gun as the RG model 40, built by Rohm in Germany. Probably worth about $100-$120 in VG condition.
20-50 USD
Depending on condition, between $50 and $75. These are alloy framed revolvers of indifferent quality.