Cheaper Solution

 is an upgrade in the Primary Monkey Knowledge tree. It decreases the cost of the Bloon Liquefier upgrade by $1,000 regardless of game mode. It requires 10 primary knowledge points invested, Aviation Grade Glue, and a one-time purchase of 500.

Prices
The following are prices for the Bloon Liquefier with and without the effect of Cheaper Solution:

Strategy

 * This lower cost for the Bloon Liquefier is handy if needing to use Bloon Liquefier to handle early MOABs and their children bloons.

Trivia

 * Maim MOAB and Bloon Liquefier used to cost the same as each other, so the respective discount effects from their respective MK, this MK and Cheaper Maiming, formerly meant the respective new prices to also be the same too. This was because the discount for both MK Points were discounting by $1,000. This was changed when Bloon Liquefier got another price buff down to $5,000 on Medium.