To make any considerable money on cabin fever you need to play like 10 games per day, and have 3 MG's, possibly 4
And to offset the price of the MG's, the backpack, and all the other shit, it's just not worth it. I got like 300 exp and 450 gp for playing a game of normal and getting like 250 kills/0 deaths. It took around 15-20 minutes... After 10 games of cabin fever you get so damn bored, they do the same thing every time and it's not even halfway exciting until round 14 or 15
1. Always join games IN PROGRESS never do wait unless you just finished an extremely good game.
2. Play only OMA, CTF, or eliim pro on small maps like junk flea or death room.
3. Never leave a game, even if you're getting raped.
Playing OMA or CTF in junk flea and death room respectively I usually get around 250exp and 300 gp every round, and each round is less than 10 minutes. Assuming you win the CTF and do fairly well in OMA of course.