Perhaps you could help us help you? Is the truck worth MORE or LESS than the shotgun? Also, I think you mean SUPER mag, the ULTRA mag if their rifle.
Are you asking what we feel the shotgun is worth? Because the basic 870 Super Mag goes for about $300-$330 depending on where you shop.
Surefire really likes their products, but they range from about $200 to about $350 fo rthe 870 model depending on where you shop.
Depending on conditon and how much "extra" stuff really comes with it would be a question for a Remington guy.
I am thinking a used gun, in good to great condition, I would go maybe $500-$550 in this market - and that would be "for a friend in need" price unless there is something special I am missing.