Judging from the simulator, the best thing to do in the actual game would be save up money, buy a bunch of keys for their current price ($1.44 per key currently), buy a lot of crates off the market ($0.02 per crate), and unbox during halloween to get the halloween effects. That's the best way to maintain a good profit. And then I found an It's a Secret to Everybody Team Captain...
It seems like if you do it normally, there are too many bad effects that outweigh the gains of the good effects.
 "Modified TF2 Crate Sim"){kind=icon}