I've grown to have a pretty good idea what my art is worth (if that's even possible). What I'm not clear on, is the additional cost for the transfer of usage rights. Is there some professional industry standard for this? I'd feel better hearing some real-world input on this than just pulling some random number out of my ass.
So here's my situation. I'm doing some designs for a major game journalism website who plans to use them on t-shirts. At this time, they haven't indicated what their budget is for this merchandising, but it's otherwise a fairly straightforward job. I understand (and will include in my contract) that no rights are transferred until I'm paid in full, but I need help figuring out what usage rights are worth these days for a project like this. Is it a set number? Is it a percentage? Does it fluctuate with the complexity of the design? What if they decide to use it on other merchandise besides t-shirts in the future?
Also, about royalties. I'm under the impression that royalties simply aren't worthwhile, and that I should just get a lump sum for my work. I'm okay with that. But are there any situations where royalties are generally included in the contract for licensed work?