Ben, You might consider driving the 30 or so miles north to Cabela's in Hammond. A good Remington 870 pump action, with both a bird barrel & a rifled slug barrel should only cost $200 or so. Add a 18" home defense barrel I think that's ~ $100 or $125
at $4 a gallon driving towards Indy makes any "good deals" a lot less good
I picked up a wingmaster 870 from Cabela's for $350 used 95%. I used my Cabela's credit card and got a $85 rebate. They have 20% off used guns right now but beware some of their prices are through the roof. Sunday the 8th is the last day of the sale.