I go to the campaing, set the number of sites to the max, put me vs a AI.
Then, all i can do is scanning. If i put money on the trip, it just gets reseted to 250, so it always asks me to press space to lead me back to the level select. I tried putting lots of money, almost no money, it always goes back to 250.

The campaign AI does not work anyways (You just instantly win once you get there), so you do not lose much.

Oh. Why do they even put a "AI" choice if its not working yet? they could only put it there when they actually made it do something...

The reason is, this game is basically still pre-release. The campaign is a very recent new feature, and the news post even mentions that the Campaign is in its alpha stage. A lot of alpha-stage stuff doesn't quite work at all even, so it's nice to see where it could go anyway.

AI is not available for the campaign, however, you can play with a friend. At this point, I believe part of the point in releasing it as-is is to have a larger testing group.

Besides, if we all keep bugging Data about infrequent releases then soon after complain about lack of polish on a release, all we're doing is complaining and not being the "loving fan-base" that some say we are.

Summary: It's in the alpha stage of development. Some things will not work to completion yet, in fact most things won't. It's a starting point and foundation.