Ditto what the others say about buying in bulk. 15W40 Rotella costs $3.50+tax/qt for me in bulk (no tax for farm use in MN).
An advantage to doing your own fluid changes is that it gets you under your vehicle for an inspection for pending trouble, even if you don't want to tackle the repair yourself. An hour under there for an oil change is well spent, IMHO.
I too have found the new vehicles to be a real PITA to work on. An oil change on our '06 Hyundai Accent takes me twice as long as my '88 Corolla because of poor accessibility.