Small Town, Deep PocketsG 20

Personally I made sure to save the first couple and recover her jewels each playthrough I did. This is $30k so with only 3 runs (save all survivors & complete game, combine all weapons, grindout cash and kills). The best place to make cash outside of those two quests is across the street from the pawn shop is the casino. Smash everything in there and close the door behind you when you leave. It will reset at any load screen and you can repeat.