25c Lighthouse Booklet Pane ($400.00!)

Last night at the spring auction of the Chittenden County Stamp Club, I placed a booklet pane of 25c Lighthouse stamps (Scott #2470-4) into the auction. According to my Scott Specialized (2014) the pane has a catalog value of $8.75 with a Minimum Bid of $4.75.

During the pre-auction viewing a member who advidly collects plate numbers came up to me and said that I might want to withdraw the lot since the pane in the Durland catalog it has a value of $400.00. AND IT DID! and Scotts had a value of $60.00 in the booklet section further back in the catalog. I had forgotten to check in both places.

It was Plate #4 on an unfolded booklet pane which means it wasn't from an ordinary booklet.

My question: Where did this unfolded booklet pane originate?

Congratulations.

Never bound (never folded) booklet panes could be purchased from the USPS PFSC (i.e., the Cave) out of Kansas City.

You could not request a specific plate number, so it was a matter of whatever happened to be pulled out of what was in stock at the time. Again, congratulations.

Apologies if I am missing the obvious, but where is the plate number? Is it in the small black rectangle?

Yes. There is a white "4" sideways in the small black rectangle. However, normally it appears as colored digit(s) on other booklet pane stamps.