I let people pick their own stats, and I charge $1 per stat point. Thus an 18 STR costs $18.
WHAT? Hey, I got to support my [far-future wargame involving space elves] habit somehow. j/k
In seriousness, I tend to use a 20-point buy or a standard array (16/14/13/12/11/10). After reading this thread, I may start using some different dice-roll methods.