Bump this back up with my own experience, shared hereon before.
I wanted a MkIII and could not fine one at several LGS or on NES WTS ads. Ultimately I bought one from a dealer in Michigan and found a local FFL that would do the transfer, but the FFL had a stipulation that the gun be old enough to make Marsha happy.
I confirmed the serial number made it seven or eight years old, the transfer was effected, and I now own a nice Hunter in stainless.
All said and done, it cost me pretty much full boat retail (including purchase, shipping and insurance, and transfer fee) for a used gun.
Then within two weeks several MkIIIs appeared on here. [sad2] Some were "post-ban" priced (really...) and were listed at more than new cost, some were reasonably priced.
Wait it out, get a feel for the market, contact local gun stores farther afield than you would otherwise drive, consider the MkIII 22/45 that B&K has listed on their website, and in general take your time if you are willing to do so... A reasonably priced unit will turn up.