I’d pay 3K for the pair.
I’d tell you to jump off a very high bridge for 3K per head.
And not so kindly ether.
Part of the problem is “IF” they can be ported out to the maximum. If not, then they can be no better than an Edelbrock/Chink knock off head. Mine went only 312cfm before a port gave up the ghost.
The other problem is an expensive valve train. TD or Jesel here kids. That equals “KA-Ching!” (AKA - Lot-O-money.)
The heads are basically stated as an aluminum square port version of the W2 & can be ported out a little further for more flow. YMMV.