Export Vipers are different in subtle ways from US Vipers.
Think speedo's and odometers read in Km. Backup lights, fog lights are differently wired. Headlights need Daylight on etc.
Extra expenses to certify in Canada, an duties are probably charged.
Makes sense that additional costs would be there. Lots of US made goods sell for higher prices in Canada also. I am in the toner business, and products that I sell in San Diego cost significanty more in Canada.
Importing into Canada has some hoops to go through if you want to do it legally.
Don't believe Chrysler warranty will be automatically granted to cars purchased in US.
Depends on what is most important to you, the cash or the convenience.
People also grey market import from other countries into US that are either cheaper this way, or not readily available from US dealerships.