J.,
Advice to me from someone else says that minivans are difficult to work on the engine... which can be why it costs more to fix.
I had a jeep but now am driving a suburban, for the space. A friend of mine has a Honda suv and wishes she had something bigger. She has two younger kids still in carseats. A Honda will hold it's value well if you go that route. There is a kia suv that is really similar to the honda. They have 100,000 mile warranty new, or 5yrs/60k for the second owner.
I had a bonneville, and it had a very roomy trunk. I would say it had as much cargo space as my jeep, minus some headroom. If I had to go back to a car, I definitely choose that over most cars available now. It wasn't the new style that's out now though. I'm thinking it was around a 95. I think 98 or 99 or older would have the same body style. Not sure how old of a vehicle you are willing to buy.
There is the infinity wagon, FX something?, and there is another like it, not sure of the make/model.. not sure about their gas mileage, costs, etc.
I would not recommend buying a saturn anything. They appear to have lots of problems with their computers. But that is just an experience of someone I know.
If you can, be sure your car seats will fit into what you buy. Carseats are cheaper than cars, but it would be a nice thing not to have to buy those too.