Intellectual Property?

copyrightSo here’s a quandary for the more IP-aware among you:

Someone I vaguely know has asked permission to use some CG artwork I created for a tutorial I wrote some years ago. This is a freely-available work that’s been published on the internet for nearly a decade, but it *is* published under a license that allows me to retain all rights outside of the website on which it was published.

He intends to put the artwork in the instructions for a kit he is selling for money, and intends to give me artist’s credit, but has not offered any recompense for the use.

Now, I’m normally not a big fan of IP in general, except where someone is earning significant money directly from someone else’s work, and the likelihood here is that a reasonable license for this small a distribution would be a couple of dollars, but somehow, I feel a tad miffed that he didn’t even broach the subject, and kinda want to ask for payment just on principle!

So, what say you, oh great intarwebs? Am I being petty and unreasonable?