No, you do not have to print the label for the parcel. You have the option of either printing the label, or applying your own postage. Just bring it to your local post office and get the postage from there. Just remember to click "Item Shipped" after mailing it.
If you get your postage from the post office, you will not be eligible for the Paypal Canada Post discount. But you can apply for a Venture One card which saves you 5% off of most parcel rates. You can apply for that at either the post office or at http://www.canadapost.ca/cpo/mc/business/solutions/ventureone.jsf
