No more than 50 USD if new in the box.
20-30 USD
Not worth more than 50 USD if in NIB condition.
@ the late 60's
About $150 if its in GREAT condition and has both the cylinders .22 and .22 magnum.
Sauer, Schmidt, Rohm
Go here - www.gunbroker.com/Auction/ViewItem.asp?Item=102096639
Could be Sauer, Schmidt, Rohm, RG, Gecado, or any of a dozen others.
15-50 USD or so
Depending on condition, between $50 and $75. These are alloy framed revolvers of indifferent quality.
To determine if you have a banned Rohm RG20, check the markings on the firearm, specifically the serial number and any manufacturer's information. The RG20 was banned in the U.S. due to safety concerns, so if your firearm lacks adequate safety features or has no markings indicating it meets current standards, it may be one of the banned models. Additionally, you can contact local law enforcement or a firearms expert for verification. If in doubt, consult the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) for guidance on banned firearms.
One for sale in my local area (Boise, ID) is going for $175.
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.