Along with what people from odyclub say expect to replace:
Front brakes every 40-50k miles (new rotors from rock auto are barely more than turning them, rotors warp quick on these heavy vans)
Rear brakes every 90k or so (same with rotors, get new ones each time, they're not expensive).
I just looked at my last several order confirmation emails from RockAuto and got decent (not basic but not top of the line) pads and rotors for around $125 for the fronts and about the same for the rear. I can change them in about an hour on a Saturday morning.
A major perk of doing your own work is knowing that it was done right, lots of dumb teenagers work at those places.