I have no idea what it's worth since there are no prior sales recorded, at least for the past ten years. As I have said before, there are covers with stamps worth pennies which are sold and bought regularly. All recorded in various places,
ebay and otherwise. So, either these are being sold as something other than what they are, or they are rare. There should be a sale somewhere. Every stamp on a cover is collected by someone.
The booklet pane (used or otherwise) is somewhat valuable, but what about a single stamp? It's value is listed as mint for $275 - $300 on The Swedish Tiger. The pane itself has recorded sales of $150 - $500. So, what is a single used stamp worth then? $15? $10? And on this point, you haven't answered my question. Is there another example of a stamp worth something which translates to a cover that is "worth just a $1"? BTW, I never said it had significant astronomical value. Just value.