I'm trying to transition into some programming consulting work. A friend of my former employer is interested in having me "develop a spec," which I take to mean come up with some technology requirements and time estimates (e.g. milestones).

Do developers normally charge for this? I'm imagining it's basically the same kind of workload that creating a bid for a project would take. On one hand, consultants don't get paid for the time they put into the legwork of a bid. On the other hand, this is probably go to be more than a couple hours of work, and my time is valuable.

Any advice? Any sites besides SO I could go to get advice with this kind of stuff? (Sorry if this isn't programming-related enough for StackOverflow! I don't know where else to get advice!)