Shortly before Bettany Mattek stepped onto Center Court to play Venus Williams last week, her business agent clinched a deal to earn her some extra money.
For $2,000, Mattek, 21, of Miami, allowed a seamstress to sew two patches across the front of her tennis outfit. One was the name of a chocolate brand, the other an Internet travel service.
The words, seen only fleetingly on television, were barely visible to the courtside spectators at the All-England Lawn Tennis Club, but they made a strong impression on Mattek's bank account.
Like the vast majority of players on the tour -- those who aren't regularly seen hoisting trophies over their heads or holding oversize checks at center court -- Mattek struggles to make ends meet.
"Any little bit helps," she told ABC News.com.
Because she wore long basketball socks and short shorts, her outfit created a controversy that overshadowed an uncomfortable fact: Mattek and dozens of players on the lower rungs of professional tennis scrape for extra dollars every day to survive financially.
Even Shenay Perry, in her seventh year as a pro and the last American to lose in singles, has averaged less than $65,000 a year.
In May, Katerina Bohmova, a 19-year-old Czech player, reportedly pleaded no contest to shoplifting about $450 worth of clothes and jewelry from a Jacksonville, Fla., department store. In her sixth year as a touring pro, Bohmova has averaged barely $21,000 per year in prize money, according to Women's Tennis Association records.
"For me, it's actually very tough," Mattek said. "Every once in a while you get to play in a big stadium like this -- Wimbledon's Center Court. It's wow, and cool. I mean [to play] the rest of the tournaments, it's a struggle."
In six months of competition this year, Mattek has won $62,002 in prize money. Her Wimbledon paycheck, for losing in the first round of singles, was $14,304, about $3,500 less than male players who lost in the first round received.
Would equal prize money for women make a difference?
"It definitely would help," she said. "It's really an expensive sport, especially for someone ranked around my ranking," 103rd in the world. "You're paying for coaches, paying for your own flights, and meals and everything."
Mattek is the first to point out that Wimbledon treats its players better than most tournaments do, extending generous per diems for meals, and free transportation within London.
Even so, the men's winner earns about $1.2 million, while the women's winner receives about $1.15 million.
Venus Williams won the women's purse last year and has campaigned for equal prize money for several years. Even though she's a millionaire, she insists it's simply a matter of principle.
"For us, it's not about becoming any more, you know, well off," she said. "It's really about an equality issue, about being created as equals, as human beings."
But for many women on the tour, it's not only the principle, it's the money, too. Some earn astonishingly less than an enterprising office worker in a big U.S. city.
As a result, the tour represents a forbidding investment for its participants. The risk of financial disaster is high.
Martina Navratilova, who has earned more than $20 million in prize money, suggests tournament promoters are greedy. She said equal prize money — and more prize money — would help avert disaster for players ranked below 100.
"Those are the people that it affects the most," she told ABC News. "It's for three quarters of the field, they lose first and second round, and they really count on this money. It could be the Grand Slams (Wimbledon and the French, Australian, and United States Opens) are well over half of the prize money that they earn for the year. You know, that's the bottom line."
Occasionally, the risk pays off. In January, a 19-year-old Bulgarian teenager flew to Australia to compete in two major tournaments. Unlike most young women her age, Tsvetana Pironkova had a serious reason to watch her pennies; her career depended on virtually every cent.
Nearly 6 feet tall and shy, she already worried about taxes as much as touch volleys.
"Everyone thinks we earn so much," she told ABCNews.com, "but in the end, it's not like that."
Short of funds, Pironkova couldn't afford to stay in a hotel catering to players. She asked an airport clerk for help and wound up at the Magnolia Court, a converted house on a pleasant side street in Melbourne.
Ranked 94th in the world after four-and-a-half years as a professional, Pironkova had won barely enough to meet expenses. Airline tickets, food, accommodations and taxes devoured her income. Taxes can take away as much as 30 to 40 percent of purses, she said.
"I won $6,000 at a tournament in Zagreb," she said, "but it was only $4,000 after taxes."
But she earned a much bigger sum in Australia and got a glimpse of the possibility of better paydays. There, the unknown Pironkova beat Venus Williams, the defending Wimbledon champion, in the first round of the Australian Open, collecting $18,300 for the day's work. (She lost in the second round).
Four months later, at the French Open in Paris, she reached the second round again, earning $26,280. Yet her expenses remained high, and her income was barely matching it.
By late last month, Pironkova had earned $83,461 for six months of effort but spent much of it traveling to 11 tournaments in 10 cities in seven countries.
Then came Wimbledon. With a first-round upset of Anna-Lena Groenefeld of Germany, the 13th seeded player, Pironkova earned significant money. Even after losing in the second round, she collected $23,366 (12,840 British pounds).
Now, her total career gross income is approaching $260,000, an average of nearly $65,000 a year.
For players from the former Eastern bloc, earning even $40,000 a year equals extremely good pay.
"They can live like millionaires," said Josef Brabenek, a Czech émigré who has coached and directed tennis development programs internationally. The government often helps with tax subsidies. "In the Czech Republic," Brabenek said, "$40,000 is a lot of money."
In the United States, though, it's not that much. Even though Mattek is having one of her better years, she still doesn't have much net income to show for it.
Here at Wimbledon, Mattek earned an additional $6,620 for reaching the second round in women's doubles and $2,380 for reaching the second round of mixed doubles.
That raised her gross income for the year to about $85,000 (including $2,000 for wearing those two patches). Stacked against airline, hotel, food, and tax bills, the gamble seems shaky, especially with a summer of heavy travel ahead.
So, for Mattek, it's one day at a time. Despite her love of the sport, in seven years on the road, her pay for playing the game she loves has averaged less than $50,000 a year.