Ask HN: What are common contractor Rates in major US metro areas?

What are "normal" software developer contractor rates in major metro areas in the US? What factors would make you increase or decrease your rates? What about an independent contractor, versus someone who is part of a larger consulting firm? What about other roles like product management, project management, and design?

Just to add some constraints, I feel like some experience levels are needed. (let me know if there are some levels you think I am glossing over) 0-3 years 3-5 years 5-10 years 10-15 years 15+ years consulting executive/investor (e.g. a consulting CTO or similarly senior roles)

I figured this is beneficial to more than just me, since it seems like these rates are less public then salaried rates, and many consultants/contractors are part of larger firms.

Also, is there truth to the 10% of starting salary commission for recruiters of full-time positions?