It's been a couple years for us, but from my recollection, there was a $450 participation fee plus an expectation to fundraise for at least $250. Then all the volunteer stuff like concession stand, pre-game meals and help with maintenance on field day. And that was pretty cheap for our area. I have heard stories from friends of surrounding schools that the expectations were closer to around $1500+ between fees, auctions, golf tournaments, advertising money, etc...
Not sure of the situation for a lot of you, but around here, the government doesn't pay anything for sports other than capital improvements to facilities and I think an extra $2000 for the head coach. All money is generated from the participating families. So balls, uniforms, transportation, umpires, equipment, money for additional coaches and everything else you can think of comes from the families. I think there is a small amount of money that comes from the overall booster club, but it isn't much.