I've read this post and a few others: What price should I charge for design services?
And Jessica's Hirsch's Dark Art of Pricing. However, what are the considerations when an agency wants you do to logos on an hourly rate? How do we factor in the very valuable royalty aspect into that number, assuming that the agency will hold all right to the logo design?
Has anyone done this for an agency before? Do you just quote them a huge hourly rate?