Destorying FOBs should give $7,5000 baseline instead of 2.5k, and you should get more $ based on how much supplies are in them.

Found it wild how much time I spent using c4 to solid snake my way through a FOB, killed two people, hacked the FOB only to discover it was packed to the brim with supplies, and barely paid for my loadout doing it.

Then I decided my team wasn't in any position and wouldn't be interested to come to defend the FOB, so I destroyed it to deny the enemy team many pallets worth of resources they had delivered to it should they inevitably take it back. That penalized me -2,500 for killing a friendly FOB. Hm. Regardless, the reward for infiltrating a FOB and hacking or destroying it is way too low.