Yeah, if you're not able to do significant repairs by yourself for whatever reason, IMO it's best to have a vehicle with a factory warranty.
DITCH the minivan ASAP !! Do a Google search on "dex-cool" and "GM Lemon" and you will see why...either the new "organic" coolant formula eats the gaskets for the ntake manifold, or they were poorly designed - or both! If not replaced they WILL fail - it's just a question of when...
As for the 3.1/3.4 intake gaskets, IMO it's a poor design mostly. The gasket is a plastic form with a silicone bead approx 1/8 thick around all the ports. I think they use this because it's a very forgiving gasket so the machining can be garbage and it'll still seal. Anyway, with age the plastic form becomes brittle and breaks and then it's only a matter of time until the silicone worms it's way out. Most of the time they leak externally but a significant percentage rupture to the lifter valley and that fills the crankcase with coolant. Even if you catch it quick and clean the engine out, it seems that too often the bearings will come apart 10-15,000 miles later.
Another engine that uses the same type intake gasket is the Ford 4.2 V6. Except that Ford went one better by placing a coolant passage right next to an intake port on cylinders 1 and 4 (both front) so that when the gasket fails it fills the cylinder with coolant. Since water is not compressible this gets you a bent rod at best, and a hole in the block at worst.