Kick plates are usually 10"-16" tall and the width of the door. Taller kick plates should be used where wheelchairs are frequently used, so that the foot rests come into contact with the kick plate and not the door surface above.
Adding a kick plate to a storm door will cost about $20 to $50.
Costs vary greatly by region (and even by zip code). To get free estimates from local contractors, please indicate yours.