I have been comparing fallout 3 to new vegas, and even when i beat fallout 3 I only had about 2000 caps.
As of now, not even halfway done with the game i have 5000+ caps.
Then again I think that fact that we can repair weapons with the same weapon makes cap conservation even more.
Just wondering, I feel like even with 5000+ caps, i generally have a hard time trying to figure out what to spend it on.