What Shot Gun should I buy I saw a Remington ?

Rem Super magnum 11-87 with synthetic stock for $650.00 and also a remington12ga 870 exp. for $200.00 or a Rem870 exp. 12ga super magnum pump for $300.00 are these good prices on these guns I thought about getting the Remington 870 exp super magnum with a 28 in barrel the guy is asking $300. OBO should I get this shotgun.