moving out to LA from Atl in late July, don't have many belongings so no van or anything, just me in my car (probably with a friend to share driving). how many days should I expect it to take, how much $$, and what's the best route? (I'd prefer to get there sooner rather than later, but if there are preferable semi-efficient routes to take aside from what mapquest.com would tell me, let me know!)
It is up to you
You can do that drive in two LONG days, or you could take 100 days.
Fastest route is I-20 to I-10 to LA. But more scenic would be I-20 to Dallas, north on I-35 to Oklahoma City and then west on I-40 to I-15 and into LA. For detour ideas, from I-40, enter I-40 into the search utility on this forum. (Route 66 follows sections of I-40 and there is plenty to explore enroute).
Money is entirely dependent upon how long you drive, where you stay over-night and what you see enroute. You could make the drive on $100, but I would suggest $500 for more leisurely progress.
Route From Atlanta
Mark has an excellent suggestion in taking the I-40/Route 66 corridor out west. It offers plenty of attractions and a variety of scenery.
The most direct route to get from Atlanta to Oklahoma City is to take I-20 west to Birmingham and US 78 west to Memphis, where you pick up I-40.