I have a spiral (fluted) bolt .308 currently. Model manufacture was late 2012.
Generally, age, doesn't have as much to do with price as Condition does. Also, stock and metal finish has a major part in that too, but bother fall under the category of condition, I would believe.
Give Mossberg a call and see what date they give you. Also, have plenty of time, sometimes it can be a long wait lol