A moon base is pretty much a prerequisite to a mars base.

If you cannot get to the moon consistently and safely you aren't going to get to mars safely either. (3 days vs. 6 months away)

Getting a base on the moon is considered a vital strategic, logistical, and safety "stepping stone" to getting to mars.

You might make one mars shot successfully but Murphy's Law will bite you in the arse eventually especially after 6 months in Space.

It requires 25"30 times less energy to launch from the Moon.

Whatever lessons you learn from building a moon base can then be transferred to the Mars Program.

Of course it would help to find an asteroid made of diamonds or gold or some exotic rare earth minerals to help pay for it all.