http://www.thefinalcost.com/
you can probably don't need to add the shipping charges
http://www.crossbordershopping.ca/duty-tax-import-guide/personal-exemptions
24 Hour Exemption – $50 CAD
If you are absent from Canada for more than 24 hours, you may claim up to $50 CAD worth of goods duty free as your personal exemption. If the goods you bring in are worth more than $50 CAD in total, you cannot claim this exemption. Instead, you will have to pay full duties on all goods you bring in. All goods must be with you when you arrive and you can not include tobacco or alcoholic in this exemption.
48 Hour Exemption – $400 CAD
If you are absent from Canada for more than 48 hours, you may claim up to $400 CAD worth of goods duty free, and must have the goods with you when you arrive at the border. You may include some tobacco and alcohol products in this exemption, and should review the section below called “Alcohol and Tobacco” for more details.
7 Day Exemption – $750 CAD
If you are absent from Canada for more than 7 days, you may claim up to $750 CAD worth of goods duty free. You may include some tobacco and alcohol products in this exemption, and should review the section below called “Alcohol and Tobacco” for more details.
With the exception of tobacco and alcohol products, you do not need to have the goods with you when you arrive at the border. To calculate the number of days you have been absent, do not include the date you left Canada but include the date you returned. Dates matter, not times. For example, we consider you to have been absent seven days if you left Friday the 7th and returned Friday the 14th.