I have an '00 Maxima GLE automatic with ~215K miles now with automatic transmission.  Here's what has given me issues:
- brakes: I used to have to replace the front brakes every 10-15K until I finally changed the rotors.  Now they're under more normal replacement schedule.
- radiator fan: bearing burned out (~$100)
- some sensor, don't recall which but it was ~$250 (dealer replaced)
- 2 O2 sensors (~$75 ea), took about 30 min each to change
So over the life of the car, I have about $500 in maintenance costs.  This obviously does not include "normal" maintenance (oil changes, air filter, trans fluid, etc.) that you'd have on any car.  If you add in the short-lived initial set of front rotors, we're at $550.  I haven't changed the MAF but it's literally a 5 minute job (I have cleaned it) and about $100.  The car could use new struts/shocks but it's not critical right now, just a tad bit floatier than it should be.
Obviously, having to do $500-600 up front would suck, when you've just outlaid $4K for the car.  But you're not likely going to find a 5-8 year old car that will require ZERO maintenance for years to come.  If that were the case, then people would routinely keep their cars for 200-250K miles.
So build in a few hundred bucks into your budget for repairs, and find a car that has a solid reputation for drivetrain, electronics, etc.