You can expect to pay about $25-$30 if you mail it overnight or 2 day shipping. I've heard Canada Post horror stories, so some people recommend doing a courier like UPS or FedEx instead. I've used Canada Post twice with no issues.
Are you applying from within Canada, or outside? We applied within, and we are about 40min drive from CPC-M. Purolator overnighted it for us for ~$30...
you can save a bit on shipping by not requiring a signature and include the text notification form instead so CIC texts you when they receive and open your application
you can save a bit on shipping by not requiring a signature and include the text notification form instead so CIC texts you when they receive and open your application