The 3.5”er Pre-27’s are available on the popular online gun auction and sales sites on a fairly regular basis - much more so than the 4”ers. The 3.5”ers are very popular but were apparently made in significant quantities as they are not rare like the 4”ers. I think you should be able to find a nice shooter (say 95% - 97% condition) 3.5” for $2K or less. I got my 3.5” Pre-27 shooter pictured below for under $1800 from a fellow member who advertised it here on the Forum within the last year.

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Terry Lester