Why your freelancer wants to be paid
Anyway, one of the most common questions I encounter when negotiating with clients is why I would be worth more money per hour than hiring someone. "Why would I pay you $25/hour when I can hire someone for $17?"
If you think you need someone full time or part time for a longer period of time, having an in-house employee might be the right choice. However, to make a fair comparison you have to take all costs into account, not just the hourly wage. Also, when you hire someone you generally have them whether you have work for them or not. Most freelancers are paid on a performance basis. If you use a third-party platform such as oDesk they will even guarantee that all time invoiced is time that actually went to your specific project.
When you hire someone, you will be responsible for payroll, taxes, providing the person with a space to work, furniture, electricity, phone, computers or similar equipment, software, internet connection, pens, paper, education, and much more.
As a freelancer, I not only need to make money to pay my bills. I also pay for my own health insurance, office space, furniture, computers, software, office supplies, and everything else I need to do a good job. I provide PC and Mac platforms, Adobe Photoshop, InDesign, Premiere, Microsoft software, camera, and much more. Some clients even demand their work be kept on a separate computer.
I often work on evenings and weekends for the same hourly pay as the rest of the days. If I need to learn something to stay on top of what I do, it's my responsibility to learn it. It is also my responsibility to do a good job.