I probably skew things toward the bottom side because I tend to think of freelance work as an "extra" and a hobby. I am somewhere in the $25/hr range but could be closer to $40 without a problem. Most of my freelancing has been to people I consider as friends in addition to being clients, so I give them lower price points.
I haven't done any freelance work with SW but I have a lot of AutoCAD (architectural) freelance work in the past. It's always depended who its for and what it is. Close friends that help me out with stuff I don't typically charge. Personal stuff for acquaintances and friends that are not as close I usually charge $20-25/hr. For business stuff I charge $50/hr. I figure if it is something they are hiring me to do so they can make money I should to. I know that a former company I worked for sold my same services for around $150/hr. so I figure they are still getting good deal on the rate. I have even traded goods and services as payment. Good luck to you.
We do both, CAD services and CAD out sourcing and like everybody else our situation is a little different. We are located in West MI.
We charge $145 per hour for my time if I am detailing a print or designing a system that requires a full simulation in OptisWorks. My time occupies me and my system regardless of the skill set required so we charge for the time not the job. We typically out source basic CAD especially detailing then pass the cost directly through to the client to help manage the total project cost. My PC should be running simulations. The CAD services we use charge the same for mechanical design and detailing and typically go for about $55 to $65 per hour.
We do not out source to persons that do not have their own business / license. I don't want to get into a project and have a contractor tell us they no longer have access to the software because their day job manager found out and shut them down.