National Cash Register Values
This is what you really want to know, but it is a very tricky subject so it may take me awhile to work this page out. Sorry!
If you send me some information and pictures by email and a small fee, I will reply with an appraisal of your machine.
Brass machines are worth min $250 for common machines in poor condition and they only go up from there, but this is a huge area of type, finish rarity, condition special features, originality etc. The values vary greatly!
plain metal machines or metal machines with the simulated wood grain cases like models 717, 720, 736 842 842-EL 852 862-2C 942 etc or machines after 1920's with gray cases or more modern electric machines.
I am afraid these machines are just not desirable like their ornate brass ancestors. The collecting world has not realized that these are disappearing as fast as the brass machines once did and soon won't be around. Thus I am sorry to say they are not worth much most are difficult to sell because they have no visual appeal. I tell people they are worth $200 or less (a lot less). The narrow, plain, metal machines (like 720) sometimes get painted in high gloss paint and labeled Coke, Pepsi, Harley or something like that. They sell for around $400-500 painted up ($150 max unrestored). In the 40-60's NCR made chrome smooth metal machines and these are sometimes more valuable for people who collect diner or ice cream parlor items. They can be worth $500.
Keep reading the other pages here about National Brass Cash registers to learn more about the value of your machine.