As usual, it depends on a lot of things. When was it made? What kind of condition is it in? How much has it been fired? Did it come with original box and papers? M28s used to be the redheaded step children of S&W's line, being a less deluxe finished version of the M27. These days, they are attracting a lot of interest on their own, so prices have been going up. Again, it depends on condition and when it was made. Well used and blue worn examples may start out around $350, nice ones will be $500 and up. Everything being equal, 4" barrels are bringing better prices these days than the 6". M28-2s and earlier (so called pinned and recessed) will bring better prices than M28-3s. They are good guns.