Uncollected Bananas auto-collect for half the amount, and Banks autocollect when full.
~ BTD6 description
Banana Salvage is the second upgrade of Path 3 for the Banana Farm in BTD6. It allows outdated bananas to be autocollected at half their original value. It doesn't help much when compared to the Marketplace upgrade, but it helps when trying to spam in higher Banana Farms without Banana Farmers or with terrible micro, as the Marketplace upgrade limits purchase of Banana Plantation or its subsequent upgrades. Additionally, this upgrade pairs well with Monkey Bank for players who desire regular automatic collections hands-off over increased income rate, although the automatic collection only starts one round after the Monkey Bank maxes out capacity.
It costs $170 on Easy, $200 on Medium, $215 on Hard, and $240 on Impoppable.
This upgrade can be paired with Monkey Banks with the "Bank Deposits" MK to make it easier to shove extra income into multiple Monkey Banks with little trouble from accidentally leaving out a number of overdue maxed out Banks.
Purchasing both Monkey Bank and Banana Salvage will make the Monkey Bank automatically collect the full amount of bank cash once the bank is full after a round.
Before Version 13.0 (?), Banana Salvage didn't mention about the interaction with the Monkey Bank. This was since added on that update. Original description was "Uncollected Bananas auto-collect for half the amount.".