Although this sets the precedent that God can supply our needs in a miraculous way, it's important to remember that God doesn't counterfeit money. He didn't create money in the fish, but rather he had the fish miraculously find and swallow the exact Roman coin that Peter needed. It's a mistake to just pray and then wait on God to rain the money down from heaven.
Luke 6:38 says, God uses men (and sometimes fish) to give finances to us. He can do it in a very unexpected, supernatural way but it will involve people and existing currency. We need to believe the Lord hears and answers our prayers and then pray for the people He's going to use to deliver the answer. This could be our employer, the person who buys our goods, or any number of people.
The Lord also blesses what we set our hands to do. When in need, we should seek God's direction for something to set our hands to and then trust Him to bless it and multiply the results of our work.
One hundred times zero is zero. Many people have missed their miracle because they never took that first step of faith and used what they had. God can give us a creative idea today that will bless us and make us a blessing to others.