In a $1/$5 game with quarter anties you need a minimum of 300 chips: 150 white ($1); 75 red ($5) and 75 blue ($10). Then the host needs quarters to break the $1 chips.

If you have a really small game: e.g., $0.25/$0.50/$1+ you may need 400 with 5 colors. Figure for the lowest value twice the number of any one of the other.

If you have a bigger game it again depends on the game. There is a $5/$10 game in my area and the same group plays $15/$30 at times or even higher. I think 300 is the bare minimum for that game as well.