system
Given the following post, respond as if you're commenting on Reddit:
human
[MCU] Where is SHIELD getting its funding?

Seriously, jet fuel and bullets are expensive.
gpt
Now, in a post-Fury world?

Do you think all of SHIELD's assets were on the books?  Off-shore holdings, cash drops, safety deposit boxes, and the like all could easily hold quite a bit of "slush fund."  

Chances are, they were previously earmarked for agents in trouble, but Coulson, as director, commandeered them.  Hell, it's still a valid use, he and his team are agents in trouble, just some of the last ones.