Today I bought a 66-1, with 2 1/2" barrel. Carried one as a Detective on the PD, and had one years ago, but foolishly sold it.
When the Dept. went to Sigs, they sold the Model 66's, and we could buy ours for $75.00. I bought both my 4" and the 2 1/2", and several years later sold them.

Bought another 4" to replace the one I sold, and this 2 1/2" cost me a lot more than $75.00.