need info on snow removal costs NOW

We have a Snow Day today because of another half-foot of fluffy white stuff overlying icy earlier-week snow, and the wind chill around -20F.

A lovely neighborhood teenager just came to my door and offered to shovel my walk. YESYESYES! Only, when I asked how much he'd like, he said he'd leave it up to me.

Help! Does anyone know what a fair rate for this kind of service is?