I've got the 500 Apotessar. I'd be careful about buying one that cheap unless I had a chance to examine it first. The fluorite element is prone to separation because its coefficient of thermal expansion is different from the glass elements in the group.Not to get to far off topic, but I think the 1st party Hasselblad V to Mamiya 645 adapter has existed for a long time? The 500mm APO Rollei lens is I believe is the same as the Hasselblad version, I could be wrong though comparing the diagrams:
Carl Zeiss Tele-Apotessar T* 500mm F/8 CF
Medium telephoto prime lens. Announced: 1982. Production status: Discontinued. Maximum format: Medium format 6x6. Mount: Hasselblad V. Slow speed. Internal focusing (IF). Built-in leaf shutter. Manual focus only. Automatic diaphragm. Heavy. Compatible with teleconverters.lens-db.comCarl Zeiss Tele-Apotessar HFT 500mm F/8 PQS
Medium telephoto prime lens. Announced: February 1999. Production status: Discontinued. Maximum format: Medium format 6x6. Mount: Rolleiflex SLX. Slow speed. Internal focusing (IF). Built-in leaf shutter. Manual focus only. Automatic diaphragm. Heavy. Built-in telescopic lens hood.lens-db.com
The Hasselblad version is only ~900USD used : https://www.keh.com/shop/hasselblad...ns-for-hasselblad-500-series-v-system-93.html
From rolleiflex.us: "Zeiss did make a very rare 500mm Tele-APO-tessar version with improved optics, but rumor is that there are only about 100 copies or less made." :/
Not even collectors, just anyone who wanted a good long lens for the 6000/HY6 series. I'm not sure why anyone would do this, the Rollei lens has to have been more expensive than the V version at any point....Even if they had it already, they could have made wayyyy more money selling it and getting the V version.
Back in the 90's (IIRC) Zeiss made exactly one 1700mm f/4 Apo-Sonnar FE lens, as a special order for an extremely wealthy Hasselblad owner. I suppose you could always ask how much they'd charge you to make another ;-).
Here it is (and yes, that's a 203 hanging off it): https://www.filmsnotdead.com/the-worlds-largest-telephoto-lens/
At a mere 564 lbs, portability might be an issue, though.