3" 19s...200 maybe?? Forget trying to find one of them unless you have serious money to part with, or get REALLLL lucky. One has been posted for sale for a few months, asking $4695. No takers yet.
I had to dig to find it, but a guy on THR posted his 3" M19 some time ago. IIRC, it was an FBI gun.
Regarding the 3" M66 - Buyer Beware - S&W also had a run of 3 1/4" 66-5s. They look
like 3" 66s (but with a FO front sight), and may even be advertised as such, but they aren't as rare (read: valuable) as bona fide