Raven Software dev Amos Hodge has tweeted a reply to a user about why buy station prices are remaining the same across all of the different modes in Warzone.
The official stance on why Buy Station prices are the same across all modes is to ensure consistency for players, so that players don’t have to keep remembering different values when jumping into different modes.
We would like to keep the prices consistent, so players won't have to memorize a bunch of different prices. We are looking into adjusting the drop rate of money based on player count instead.— Amos Hodge (@wendellwobble) April 15, 2020
However, Hodge has stated that they are looking to adjust the drop rate of money based upon player count in game. This would vary the amount of cash players can find depending upon the amount of players in each mode.
There is no confirmed time frame for when this changes will be released, but it will be interesting to see by how much the cash drop rate is effected based on player count.