Buying chips is
always
helpful when it's possible to do so. Some chips are more helpful than others.
Normally, when you draw a chip, you have to immediately play it, like so:
Farren draws an Orange 1; Farren plays an Orange 1 and moves forward 1 step in the cauldron.
Farren draws a Bomb 3; Farren plays a Bomb 3 (whether he wants to or not), moves forward 3 steps in the cauldron, and is 3 steps closer to exploding.
etc etc.
When you draw a blue chip, you can choose not to play the next chip you draw. That chip goes back into the bag instead (where it could be drawn again on a future turn).
Farren draws a Blue 1; Farren plays a Blue 1 and moves forward 1 step in the cauldron.
Farren draws a Bomb 3. Farren uses the Blue 1 to toss the Bomb 3 back in the bag instead of playing it. Farren does not move forward in the cauldron, but does not get closer to exploding either.
It only applies to the next chip, so in circumstances like these, its power doesn't help.
Farren draws a Blue 1; Farren plays a Blue 1 and moves forward 1 step in the cauldron.
Farren draws an Orange 1; Farren could use the Blue 1 to throw the Orange 1 back in the bag, but why would he do such a thing? Farren plays the Orange 1 and moves forward 1 step in the cauldron.
Farren draws a bomb 3; Farren plays a bomb 3 (whether he wants to or not), moves forward 3 steps in the cauldron, and is 3 steps closer to exploding.