Is there any way to add a few hundred miles to an account?

I know you can buy miles from Aeroplan at 3 cents, but I think that is true only if you already have 70% of the miles available. What if you have, say, 10200 and you want a 15K mile award, so you need to add 300 miles.

Can you get a Sobey's card for someone else and use it to add miles to their account?