Any price list that is a year old is probably out of date. Just as an example, consider a Zenith TransOceanic H-500 from 1952. Nice radio but not particularly rare since about 250,000 were made between 1951 and 1954. In addition all collectors must realize that there is a difference between real value and collector value. Finally, all should be aware that there is a difference between asking and selling price.
Neophytes often pay too much as do non-collectors.
Real salesmen are aware of this. From personal experience I have found that if someone does not know what the value of what they have is, they probably are not able to properly assess its condition either. Moving Between Classes As a rule of thumb, between classes the prices usually double however the effort involved with moving a radio up a class is exponential. It is not too hard to move up one class, very difficult to move up two, and must be a labour of love to move up three. Also be aware that until recently, a higher premium was put on appearance than operation.