I wrote a fan-fiction story and had emailed a company to get a license from them so I could publish it. (The license would cover copyright stuff, etc.)
However, the person in charge of licensing asked me how many copies I planned on printing... 1,000, 5,000, 10,000? I admit that I hadn't thought about that. I just wanted to self-publish and put my story out there, and if someone wants to buy it, great. If not, I'm still a published author.
What if I just want to print out 10 copies?
Make sure you have permission first before you do anything. I tried that with a fic of mine and they flat out said "No" and that I was not entitled to self-publish or make any money as long as it was based on their universe.
I don't think you should plan on a specific number. If you plan on a small run, tell them it's small (less than a thousand). Maybe ask them why they want to know how large you're going for so that you can answer better. I think your answer should actually be that you don't know and that you plan to do "print on demand" which has the capability to grow, but would only print a copy when you need to print it. You should not print 1000 copies if you can only see yourself selling or even giving away 10.
My guess is that they are planning to offer to charge you a license fee and that depending on how big you're going they may want to charge you a different fee. That or they want to give you a license to a specific number so that if you go over it you have to negotiate paying them more.
