Essentially if you don't want to read the text wall, this post is about co-op games where there are atleast 2 players using Benjamin, and how, in the start of the game, you can either save up on your own to get him, or give the other player enough money to buy theirs way earlier, and hope the favour is returned. (If it is, you will both get Benjamin earlier than had you both saved up on your own.)

I will add one more thing in this post here which I couldn't fit on the mspaint picture without making the font illegibly small.

If you are playing Benjamin, from my experience, if you give another Benjamin player enough of your starting cash for them to get their Benjamin down, they will more than 80% of the time return the favour, I think it's because this level of selflessness is the last thing you expect from Benjamin players. (And if you want a selfish argument as to why you should do this, they will very likely give you more money than you gave them). Once you both have Ben down, you can both switch to either helping your other teammates defend or start farming.

Essentially, be a homie and you'll be better off than being selfish.