you can also go to your local value village.
a good bag of toys with electronics/lights/sounds will usually run you a couple dollars.
get'em and gut'em,as a bonus,you also get free small machine screws for future customs
police cars
helicopters
tanks
playskool rescue robots(good electronics,but more of a p.i.t.a to take apart as almost every mold seam/join area is glued and screwed)