If you pay to have your tiles installed, your installation company may actually charge you a fee to move furniture out and back in again after the installation is complete. This is another cost that can be avoided if you install your own furniture (of course, everyone may not be physically able to move all of their furniture alone!).
Removing Old Flooring
Consider the current flooring you have right now and how difficult it would be to remove it. This cost can be pretty hefty depending on what you are walking on right now. Do it yourself to save some money and relieve some physical stress in the process.