A lot depends on what is an error pin.
If a mistake is made, there are several choices:
1. Stop all distribution and destroy all that have not been sold. In this instance there is a real error, and any that are not caught and destroyed will tend to have a high value.
2. They go ahead and keep selling, saying "oh, well" or words to that effect. This can be something like the "Januray" pin where nothing was done, or it could be like the "Davy Crockett 1947" where there was a supllemental "Davy Crockett 1954" released.
3. There are "variations", such as one Minnie Mouse pin JudySue has where we have seen, I think, nine different color combinations. It is not likely that any of the variations has a higher vale than any other, and there is nothing which would increase the value of the pin.
4. Then there is the problem where they try to make good. An example would be the musical and light up Mickey and Minnie from the SSPE, where either the light up or music was defective. Disney is replacing these on an even exchange basis. Only the future will tell which will have a higher value, the working pins or the defective ones; my vote is to the working pins.