It sounds like home defense is your primary objective with the scattergun. About a year ago, I built the pictured tactical shotgun for right around $200. Here's how: New 870 Express from Academy, $215; Knoxx stock, $100; 7-round mag extension and barrel clamp $30; 18" Factory Remington barrel, $90; Totaling $435. I sold the 28" vent rib barrel ($155) and factory laminate stock/forend ($90) both on gunbroker.com. Grand total $190! Looks like you have $160 left to buy a great used field gun!