reaches further under the couch cushions Wow, it's like there's a whole bank down here!
I don't get the "meaning" of the sentence, is this a Portuguese expression or just a weird sentence?
Descobrir can also mean to find which makes a lot more sense in this context
The preferred English sentence is very odd!
The preferred solution ought to be we can find more money, i.e. We can go about getting more funding.
Find out is not used that way. It is used for information, about events, and even for how to do something. Here, you simply use find. Discover makes little sense in this sentence, and to my mind is wrong.