I'm a big fan of the Sheridan pneumatics for backyard pest control. They make a bit more noise than the spring-piston guns, but the .20 caliber pellet will cleanly kill anything right up to a possum. Plus, you get variable power so it's not out of the question to shoot it in the basement or the garage. Should be able to get a rifle for $150-$170, and a pistol for a little less. The pistol, unless you can find an older one, will have to be .177 or .22 as the .20 has been discontinued. The rifle is easier to hit with, and can ultimately have more power, so it would be my choice. Mine is head-shot accurate from anywhere inside the house to anywhere in the yard. By the way, I just got my '62 vintage rifle back from Mac1 Airguns, who did one of their "steroid" conversions on it; it now breaks 800 fps with a 14.3 gran pellet. About twice the power of an average spring-piston .177
