Serena Williams is poised to make history when the U.S. Open starts on Monday. The 33-year-old will vie for her first-ever single season Grand Slam sweep, having already won Wimbledon, French Open and the Australian Open. It’s no wonder tickets for the U.S. Open women’s singles final sold out before the men’s final for the first time, ESPN reports.

As of Friday, men’s final tickets were still reselling for more than the women’s, with tickets on StubHub starting at $223 and $195, respectively, for upper deck seats and at more than $3,200 and $2,000 for courtside seats. But as the prospect of Williams becoming the first woman to win all four Grand Slam tournaments in a single season since Steffi Graf completed the feat in 1988, Forbes reports resale prices for the women’s final will rise, perhaps even surpassing the men.

One thing is for certain, however, judging from Williams’s ability to move tickets — Serena sells. That seems like a no-brainer when talking about a 21-time Grand Slam winner, but it’s not. Despite Williams’s nearly unprecedented dominance, she’s somehow still not at the top of the tennis world’s endorsement pay scale. Maria Sharapova, who’s won five Grand Slams and has a 2-18 record against Williams, rakes in $23 million annually in endorsement cash, according to Forbes. Williams, meanwhile, makes $13 million off endorsements.

“If they want to market someone who is white and blond, that’s their choice,” Williams recently told the New York Times Magazine when asked about her place as only the second-highest paid women’s tennis player on the Forbes list. “I have a lot of partners who are very happy to work with me.”

They include Chase, Audemars Piguet, Gatorade and Pepsi among others.

As the tennis world evolves, however, and top players start veering away from old stereotypes, Williams could finally find her way to the top of the Forbes list — especially if she captures another U.S. Open title.

She’ll have to first make the final, which could present a few challenges, including possibly meeting Sloane Stephens, who beat Williams at the 2013 Australian Open, Belinda Bencic, the player to most recently beat Williams, Madison Keys, a semifinalist at this year’s Australian Open, older sister Venus, and Sharapova.

Despite what’s at stake, though, Williams is remaining calm.

“I don’t feel that fresh pressure,” Williams said Thursday (via Sporting News). “If I make it far then maybe I will but, as of now, I really don’t feel any. I’m just here to perform and to do the best I can.”