I worked for a design agency 6 years ago that charged clients $120/hr for services. It makes sense because as a business you need to charge overhead, to be able to pay for wages, lease, equipment, etc. That marketing agency is probably charging more now.
A lawyer’s office will charge you $300/hr, so the $120/hr with the design agency is not bad. I’m only charging $50/hr right now, but thinking about upping it to $100/hr to properly cover overhead charges. Plus, if you plan on staying in business, you need to charge overhead or you’ll sink.