Depends of course on your specific situation and how the currenttile is put on, but generally speaking tile runs from just over $1/SF on up - typically around $3/SF for what most people choose for a normal tile floor. Removal of old and install new typically around $10-20/SF for labor and all other materials and tools - $15/SF is a common "median" that is quoted, for run of the mill installation with no special patterns and only normal cutting in intricacy.
Of course, get fancy with type of tile and you can get to $50-100/SF with no problem - or get caught by the "fad" tiles like the $40-70/SF recycled glass on in a question yesterday and you can easily be in the range of a marble or granite floor.
Click on the Home > Tile link right under yourquestion for lots of other questions with responses on tile issues, including typical cost info.
