Why Did This Queensland Cover Go So High?

Nothing jumps out to me as the reason this would hit US$750+.

Is it the etiquette, one of the handstamps, a particular rate, or something else?

https://www.ebay.com/itm/257078011656

All I can see is it was registered 12 Dec 1912, not 1913. I'm no expert, but it seems mailed before the Confederation was formed, and received after.

Interesting. The postal cancels on front are dated January of 1913. So it was registered days/weeks before actually being mailed?

It's a very late usage. Australia united in 1901. Might be an illegal use, one that should not have gone through. Just a guess, but it's very late for sure.

Stamps were issued until 1909 with this design.

The registration label indicates it was mailed from a Traveling Post Office, aka "T.P.O.". That is most likely a train, and this is comparable to the US Railway Mail System of loading mail on the train, and having clerks who would process the mail enroute to the destination and points along the route.

Based on my experience with other Traveling Post Offices, covers from these offices are often much less common than mail from a traditional post office. A registered item is probably more uncommon.

The mailing date looks like December, can't quite make out the day. Mail from Australia to the US was a few weeks, and across the US was another 2-3 days from San Francisco to New York to Floral Park.

We really need an Australian specialist to help out here.

Although united in 1901, the first stamps of the Australian Confederation were issued in 1913 after some design competitions. So the use of the Colonial Stamps continued for a bit past 1913, of course. I guess this could be considered one of the last used of the Colonial Stamps before the Kangaroo and Map Series became widely used. Since there was no official First Day of Issue of the Kangaroo stamps, it can be determined from postmarks that the 1d Red was first used on January 2, 1913.

I looked up John Lewis Childs from Floral Park and he was a horticulturalist and statesman. Possibly had to do with the receiver.

The stamps appear to have been cancelled 9 DE 1912, or 9-12-(1)912.The registration was 12 DE 1912, or 12-12-12.

It's most likely to do with the TPO registration label.

Was the violet 'REGISTERED' handstamp applied in Brisbane? If so, it's probably not rare. If it's a TPO marking then that's a whole different ball game.

Postmark Reveal was able to pull just a bit more information off of the front cancellations.

It definitely has the word "DOWN" which would indicate the direction of the rail. The remaining information appears to be "9 7P 12" so maybe is was "DOWN 9" and "7 pm"??
Not an expert by any means.

"DOWN 9 DE 12" I'd say

@revcollector: Australian States stamps were valid for postage until 1968!

No, although it looks like 7P, I think it is just a malformed DE.
Found this:
https://queenslandhistory.blogspot....ng-post.html
It shows many styles of the DOWN TPO cancel, all of them with dates in the standard DD MM YY format, so "9 DE 12" would make sense. The top line may read something like "T.P.O. Nº 3 S & WR" (or similar, depending on which RR).



p.s. @revcollector Congratulations on 10000 posts!