What are the fair market values for a used S&W Model 29 (44 Mag) with 4" barrel and a Model 610 (10mm) with 5.5" barrel? Both are in excellent shape.

Would firing 44 Magnum cartridges out of a 4" Model 29 be too painful? My friend said he never fired the Model 29 more than a couple cylinders at a time. Or he just shoot 44 Special to enjoy the revolver more.