1 Residential garbage disposals with a 1/3 horsepower (HP) motor cost about $50-$115; a 1/2 HP model runs around $60-$180; disposals with a 3/4 HP motor are about $120-$350; and 1 HP motors can be $150-$380 depending on brand name and quality of construction. If you can't install the garbage disposal yourself, it's generally not a difficult or time-consuming process and you can usually hire a handyman, for anywhere from $30-$150 an hour.