I've heard anything from as little as $25 an hour up to $300 an hour.
I think it all depends on how good your designer is. If someone can't do diddly, how can you charge a customer based on someone not all that good ??
We charge out by the hour at $145.00 an hour.... or purchase a block of time for $$XX amount of dollars.
No offense, but this hardly seems like a fair question. Not knowing if this person can design wraps, logos, paste up or even hand draw when needed for added touches vs. someone who can barely cut and paste things together and find them quickly on google. Is this person truly a good designer ?? That's the real question. According to what you pay him/her, will determine a starting point. If I had someone on the payroll at maybe $15 an hour, I highly doubt they're gonna be any good at designing much of anything. So, using someone to find things on the internet and slap crap together is worth maybe.... $35 an hour shop time.