When I say not generally, I'm saying where they tend to trade and not that one that sells at high water mark. Having a intake on eBay for 5k also doesn't mean it sold for that. I have sold two of these said intakes . One i sold a buddy and cut him a deal on, the other I got what I felt was market value. Usually a set of heads with matching intake will be in the 5k range. As for the F , Robert Pond sells them brand new for $2250 plus the ride. Attached is the last complete set that I know that sold. https://www.fordfe.com/viewtopic.php?f=664068&t=168897&p=1143166#p1143166

I believe the "Rev-Kit", is an early ProStock Engr. design (adaption) for an FE; reinforced by the use of PSE rocker shaft end stands, retained by the "longer" cylinder head studs.

Time frame would fit everything else in the picture as well!

Sadly that is largely how its always been. I think it was treated as hey look what I got and you don't. Jim was hard to get along with at times, and his QC would be considered the same. His son , and possibly a brother have been sort of over it as of late , but his son Dave has a terrible rep him self. I know Jay and Kurt tied to buy the stuff but it got blow up also. Such a shame that they would rather see it die than be used. 

https://www.fordfe.com/nos-bbm-2x4-tunnel-wedge-62-bench-seat-shifter-63--t171043.html

Mine on old forum, thanks for space Jay!

Joe is a top notch porter. His price is the manifold plus him porting it which is very expensive today. Your not comparing apples to apples.

3k-5k for intake , No not generally .

They made standard high riser port location and raised port location in them.

There is a XE 2x4 also. The D is sort of angled in the center like an X so is the XE. The High riser has its own carb spacing on the 2x4 stuff because the carbs from the factory used metering blocks front and back. Ive always heard the F intake is a good 25 plus HP over the D . Dove made the tunnel wedge for the high riser but it is usually only for the raised port heads.