I got paid $11.00/hr for my first CFI gig doing Pt. 61 instruction at an FBO. This was a few years ago. I only lasted 6 months and moved on to another FBO in a different state doing Pt. 61 & 141 instruction. I started at $16.50/hr there for ground/flight instruction, scenic flights, MX flights, etc. We also got paid $8.50/hr for paperwork, talking to walk-in students, meetings, etc. I did some Simulator instruction as a contract CFI for an aviation college and got paid $25/hr for doing that. We didn't get paid for MX cancellations.

The bottom line is, CFI pays sucks. Flight Schools charging $50/hr, while the CFI doing all the work is only getting between $10-$20/hr. To make money as a CFI, you need to work at a school teaching foreign students (TransPac, IASCO, etc.)