For GFCIs I bought a 10 pack from E-Bay before Xmas. It was $100 with shipping and another $47 for Duty etc. Still saved $50.
I just looked and that vendor has bumped the price to $150, so no longer worth it after Duty. Guess I got lucky buying when I did.
If you only need 6, they come in 3-packs for about $40 in store.
But, if you don't care about code, you could use 20A outlets on your 15A system. Here's and example of no-name ( factory ) ones you could consider. It's a 10 pack shipped for $80
http://www.ebay.ca/itm/Lot-10-White-...item5ae5f01992
I bought Leviton Smartlock Pro, similar to these
http://www.ebay.ca/itm/Leviton-8899-...item3f150ecdc8
If you do buy from outside Canada, don't forget to factor in Duty and Brokerage