I know we have the technology, but how practical/beneficial will it be to have one?
It won't pay off for a good 20-40 years to be sure, but it would be heavily beneficial to the US. We'd own the fricking Moon more or less and anyone who wanted to get resources from it would have to contend with us. It also serves as the optimal location to blast off to asteroids and other planets compared to Earth.
The cost to start up a Moon Base is .5% of the current price the War on Terror has cost us. And to those saying they won't see it pay off until near the end of their lifetime, every generation will use this bull shite excuse until China or Russia make it there first. We need to grab the bulls by the balls if we are still to be the dominant super power for centuries to come.