I think funding another moon lading is a waste of money. There is nothing about the moon that holds the key to mars. You go to the moon, because the moon is still interesting, not because it's a stepping stone to mars.
There are plans for going to mars. One is called Mars Direct, the other called Mars for Less. A few countries, notably Australia have have their own plans, but all of them are basically the Mars Direct plan with different rockets. In a nut shell, they say every 18 months Mars's orbit gets reasonably close to Earth. We could send a "Earth Return Vehicle" six months in advanced. Then send a crew of 6-8 explorers who will live on Mars for 18 month, then return back when the planet is at it's closet orbit. This plan is estimated to cost 55 billion dollars.
The "Mars for Less" is highly controversial. It proposes we send an explorer to live on Mars indefinitely by sending a team of explorers on a 500 year mission. We send them with a return rocket that's lacking in fuel. The idea is that while we are terraforming Mars, we can use the natural gases to create rocket fuel there. Its not clear how much we'll actually save, but just the fact that we are sending explorers to Mars indifferently is enough to kill this idea. I remember listing to this plan on NPR radio, and the radio host asked the question... is it ethical to send a team of willing scientist to mars with no plans of a safe return?" People made arguments for and against, but it was a really heated discussion. What if they get sick, what if they change their mind, what if things turn violent or a disaster happens, etc.
