I agree completely with Winston.
This is a neat variety - definitely well worth having. It is a noteworthy double transfer, since it is so easy to see. That alone, should give it a modest boost in price/value. But...
I have always thought that this variety was grossly overvalued by Scott, however. I suspect that probably all serious 3c collectors who have been at it for over 10 years have at least one of these, and none paid over $100-$500 to get it. Most, probably got it very cheaply on
ebay. The couple higher realizations you see at Siegel I'm sure were not to serious, experienced, 3c collectors. I bought one on cover, from a 3c collector-friend for a couple hundred$. These are very obtainable, for one who looks. For the casual observer, they probably go by unnoticed and not described in some auction lots.
Why do these not stand out so much? Because they are not as "important" as some other stamps. They are neat, fun to have, but not super rare, and don't have any extra degree of importance attached to them that would make them worth another order of magnitude in pricing.
Its easier to illustrate by example. I'm better with the 1c stamp, so I'll use 1c examples -
99R2 - Scott #8/#21 - Ty III. Massive double transfer, but the reason that it is important, is because it is the best example of Type III of the 1c stamp. Also this one is Ty III due to being intentionally short-transferred, as opposed to many others, that were Ty III due to plate wear or plate finishing/burnishing. So this is distinctive in that sense as well. To those interested in the plate manufacture process, it also shows that Toppan Carpenter were still having major issues perfecting plate making with a 3-relief transfer roll.
10R4 - The only recorded double transfer on Plate 4 of the 1c stamp. It was clearly the first position entered when the plate was made - they started, stopped and started again, so it would seem. 10R4 is also one of the Top-row A relief Ty II stamps which are somewhat coveted by many 1c collectors due to their relative scarcity and complete top designs. They are also an interesting study in and of themselves.
The point I hope I've clarified is that a double transfer alone is not necessarily a tremendously valuable item. It depends on context, and degree of importance. Importance drives demand, and then, supply, if not met, can drive the price up exponentially at that point.