What are the price differences between new carpet, hardwood, wood laminate, and ceramic tile?

What is the cost per square foot (the average for medium-quality) for each of these? I would probably just get them from Home Depot or Lowe's, unless somewhere else is less expensive. Does the cost include installation? Thank you.

You will have to go out and price this for yourself.
I would say that carpet and tile is your cheapest but carpet may be the cheapest first then tile and then the hardwood, wood laminate. Get your measurements and go to a Home Improvement Store and let them tell you how much you will need of each product make sure you have picked out some patterns before you ask for help.
Yes you will have to pay for the install. (good padding is the life of your carpet)
You may want to try Sears for the carpet and install or buy the flooring and hire an independent to do the install. I have dealt with both the home improvement store and their installers suck. My carpet is still not right and that came from THD...

I would look to bamboo flooring from Lumber Liquidators. At under $2 a sq ft, it's fairly cheap and will last a very long time.

I had a friend do a self-install for a fair sized room for $500.

Laminate flooring would be my reccomendation. It isn't much more expensive than carpet, and I personally think it is worth it. Easly clean up, and no dust mites!

carpet based on quality of padding can range .89 cent to $2.00 a sf and an additionl 200 to 400 depending on size of room and additional required like carpet tacks, removing reinstalling trim etc. but a carpet installing company can save you by packing it all into a flat price. many adds running Empire comes to mind to name as 1.
Hardwood is $1.50 to $6.00 per square for mid grade. Install here depends heavily on conditions but typical range is 400+ based on area your in.
Fake wood or wood laminate is cheaper then hardwood per square but same for install due to time to install.
Ceramic - most expensive starting at $2.00 per square this is a labor intensive project typically done over 2 days with diamond tile saw the labor for this project can reach $2,000 no matter the quality of the tile. the more intricate and smaller the tiles you want to use the more expensive the labor gets.
hope this helps