To answer your last question first, yes people still carry Sig 239s. It's a good quality, very reliable gun. To set a price for yours, I suggest you back out the holster, or at least describe it by manufacturer and type; IWB, OWB, etc.
Not sure what type of Hogue grips you have. If it's just the rubber wrap-around ones they sell for around $20 so that won't change the price much. Do you still have the factory grip panels? How about the original case, manual etc.? And finally, what is the condition of the gun? Field strip it and check the "smiley" wear on the barrel. Run your fingernail across the smiley and see if you can actually feel a worn area. If not, it probably is a reasonably low round count gun, or was lubed well before shooting. Is the gun finish good? Any holster wear or scratches? All that stuff will be used to set the value.
Until you describe the above, it's pretty hard to even give you a ballpark, IMO.