The thing is, they actually are more rare. What I mean when I say this is that
Machine Doubling is not a variety. It is an error that usually happens during the ejection process. By definition, each error is unique. You may find several that are very similar, but none that are exactly the same. Here is the rub. You would most likely find more machine doubled 1972 cents than you would actual doubled dies. Since they are all grouped together rather than looked at as unique as snowflakes, it makes them more common and less collectible. True collectors of doubled dies would not even look at your coin with any kind of awe or amazement. There are people that collect extreme examples of
Machine Doubling like the one you have. Those folks have been more visible and more vocal lately.
Machine Doubling has taken off in popularity. You also have those uneducated collectors that just do not know any better. They see a coin like yours and immediately feel it is a true doubled die, no matter how you explain it to them. Some educated collectors feel it is taking advantage of the not so educated by selling coins like yours. Me, I believe the buyer is ultimately responsible to have the education needed when making purchases. That feeling goes out the window when an educated seller is outright deceitful when telling what this phenomenon really is. You coin would sell for $3-$5 on
ebay for any year other than 1972. Being a 1972, I feel it could sell for $10-$20 on
ebay. Will it be an educated buyer or not, I cannot say.