Non-profit commercial license

So I was contacted today by a international nonprofit to use some of my images for web, multimedia and print. They want a creative commons non-commercial license from me and I am ok with that. However they did say some of their printed publications are sold. They said this covers the costs of printing shipping ect...my question is:

What is the definition of commercial?
If it is being sold is it commercial?
or does it have to be for profit?

If any of you have any advice I would greatly appreciate it.

Here is a copy of the email:

"...We would be interested in using your photo for our websites, power-point presentations and print publications. In terms of print publication, most of our publications are free and available on the website...many under Creative Commons licenses themselves, but a few do cost money. The cost is to pay for printing and shipping..."

Thanks,