Used Booklet Panes And Singles

I saw this nice looking used booklet pane 319g on ebay for a good price ($99 vs cv $450) but then I noticed the postmark is from 1996. oops. You cannot take a $125 CV (unused hinged) item and add a modern postmark to turn it into a $450 item. it is a pretty space-filler though.

I also saw this one, for a not-so-good price of $149. The pencil cancel does feel contemporaneous but even if so, who can say if the booklet pane served actual postal use or did some kid just scribble over the stamps.


My question is about used booklet singles. They aren't priced in Scott, but how common are they? Are booklet pane singles valued as a nominal 25 cents (or less because they have a straight edge), or do they hold a modest premium value above the basic sheet stamp. The scarcity of the $450 intact used booklet pane of 6 doesn't really give any insight to the value of a used single.

I have a collection of used margin copies, guidelines, and other position pieces of sheet stamps and thinking about adding some reconstructed booklet panes to the collection. I don't see anyone selling these early used booklet singles except on cover. Is this because they are so common and cheap that they aren't worth listing, or because they are relatively scarce that no one has any to sell? My guess is that the supply is very small compared with the sheet stamps, but the demand is near zero, with very few collectors seeking these out, so dealers don't spend any time to look for them or even to set them aside when they find them.
Thoughts?

Sometimes you can see a seller arguing that 1 booklet stamp = 1/6th the value of a complete pane of 6. That equation doesn't hold water. Particularly with the oldest flat plate booklet panes (up to around 375a), used full panes have high catalog values because they are rare.

Sometimes only a few examples have survived, llike for example, a used 300b. Used single stamps of 300b are not scarce at all (a recent auciton had a bulk lot of over 100 post cards with 300b's). Already when it comes to booklet pairs, my observation is that covers sell around a few $, a booklet block of 4 on cover is already rare.

The generic rule is that a booklet pane on cover should be of contemporary use. That basically means it should have been used before the following pane issue was available. That period was of very short duration for some issues, so a few more months is acceptable, often described as "late use". However, the 1996 pane above clearly is of the "find a fool" type and has no philatelic value. With off-cover used booklet panes, it is a question of whether it can be tracked back to contemporary use. Rare off-cover old booklet panes often have a track record of ownership going back decades. Sometimes one shows up at auctions but rarely sells or only at a fraction of catalog value.