I sold an 870 Special Purpose for $475 on Gunbroker last fall.Since 1964 essentially all pump shotguns are "modular with swappable barrels and stocks." Nothing unique about that. This shotgun will not wear well. The whitewood birch stock is stained walnut. Every little ding will show through white on a dark background. Blech! The Mossberg 500 is serviceable enough but clunky. For $400 you should be able to buy a used 870 Wingmaster and it's ten times the gun (avoid 870 Express!).