If buying two small different items, from the same seller, in a single parcel, shipping cost change?

[reallynicestamps]

Up to the seller.

Before bidding, use the Contact Seller link and ask.

Also confirm that he does ship to Canada and how much it will cost.

You should be aware that if this note appears on the listing:

Customs services and international tracking provided

that the seller is using the Global Shipping Program and CANNOT combine or discount shipping.