Pricing question

[LeSueur24]

Hey, new here. I recently got a message on my Flickr account from somebody who wanted to use a picture of 2 elephants I took for "gift items" which I'm thinking are things like mugs or t-shirts. He offered to give me free samples of the items he sells or give me money for the photo. I asked for a website he could give me to show products, and I'm waiting for a response back.

My question is, depending on how much his stuff sells, what would be a good price for my picture?

Link to picture: http://www.flickr.com/photos/alexlesueur/2058671504/in/set-72157603278918273/