How much will it cost?
The cost of a trip to the moon according to Bush is $12 billion. This is just for a manned mission to the Moon. This does not include the cost of the proposed future lunar colony, just one trip to the moon.
Is it feasible?
Sending people into space for extended periods of time leads to a lot of health risks. Is it worthwhile to send humans to Mars if they return with cancerThere is an increased chance of getting cancer for anyone traveling to Mars. Cancer is not the only risk to a space traveler's health.
There are some basic parts of colonization one needs to understand before they can decide if colonization is feasible, let alone profitable.
What could a colony or space station provide for the people of Earth?
Tourism is also a benefit of space exploration. Many people want to travel in space. Today for the right price some have experienced space flight first hand.
How would they power themselves?
The Moon also has resources that could be used to power a lunar colony. Here is a map showing the Moon's resources which include uranium.