The money part sucks, but its gotta be done. From my experience, its best to collect every single penny up front and threaten the "if you don't pay, you don't play".
This year, my bro had the nerve to tell me he couldn't fork up the $40 because he had to buy all these tools for his new job. The kicker, he told me during a poker night where he just came from his fantasy baseball draft. My dad is in that league, and the next day I asked how much the buy in was, he said $150.
In the end, he ended up paying at the first game, but why even say you won't have the money, just stay quiet until you have it.