I know that there were four Panhellenic games that would cycle through Greece each year. Did the participating athletes dedicate all of their time to training or was it mostly a hobby? Did they work normal jobs like everyone else? Were they wealthier than the normal person? If so, by how much?
Classical period athletes were amateurs insomuch as they did not make a living from being an athlete. While cities would certainly honor Olympic victors (at Athens, for example, Olympic victors received free meals for life, while at Sparta they had the right to fight in the king's bodyguard), they did not pay for their training. This meant that athletes came by and large from the leisure classes of their cities, since only men who were rich enough not to work could afford to spend the time in training necessary to compete at a Panhellenic level.
Just how much richer an Olympic athlete was than the average person probably varied by sport. Competing as a wrestler only required that you could afford to spend a great amount of time training. Entering a chariot, by contrast, meant you had to have the money to train and maintain a team of horses, a vastly more expensive undertaking.