Snow Leopard is available in the online Apple Store for $29 USD for a single-user license, $49 USD for a family pack (5 licenses) in the US. In Canada you can get Snow Leopard for $35 CAD for a single-user license and $59 CAD for a family pack (5 licenses).
All of these are available with free shipping or $13 CAD for expedited shipping (in Canada). Expedited shipping is imaginably the roughly the same in the US.
