How much does it cost to install ceramic tile floors?

I am a contractor, have been for 10 + years and my company charges $4.75 per square foot. That includes your durrock and underlayment. However it DOES NOT include you tile or grout. When you get into walls, showers, or irregular areas the price does vary. If you have 3/4 inch subfloor don't let anyone else convince you that you need any other underlayment or anything such as that. It is not necessary and they are simply selling you what you don't need. If you are wanting a heated floor system mats are not the way to go. We use a heater wire that comes on a roll and is much cheaper and much easier to install.