"It's degrading. This box would cost me $100.99 in the U.S.," she tells CBS News national correspondent Byron Pitts. "I am getting it from the Mexican side for $27."
There are similar stories from other U.S. citizens who cross the Texas border into Mexico for their prescriptions, doctor visits, dental care and even surgery. People from as far away as Iowa, Minnesota and Illinois.
"The healthcare system in this country is a travesty," says Gana Jones, a truck driver originally from Dallas. Like 47 million Americans, she has no health insurance. Her choice? To live within driving distance of Mexico.
"I can come over here, I can get an X-ray for $25. I can buy my prescriptions for about 60 percent less than I would have to pay in the U.S.," she tells Pitts.
For Perez, the dark reality is health care in Mexico is her only affordable choice. A diabetic, she lost her job at a windshield wiper plant six months ago. Few if any employers in Brownsville are hiring full time a 46-year-old with a pre-existing medical condition.
Her doctor of four years will no longer see her.
"Suddenly, you lose your job, your health card and then they don't even know you," she says tearfully.
From Perez's House in Brownsville, Texas, it's a 20-minute drive across the border into Matamoros, Mexico, to pharmacies, medical facilities and savings.
Her doctor's visit in the United States cost her $125. In Mexico: $3.
We asked the Clinton and Obama campaigns how their health care plans would help someone like Rosie.
Under Clinton's plan, a person like Perez who has virtually no income would receive government-subsidized health insurance but she would still be required to pay a small co-pay. And Clinton's plan could lower Perez's prescription drugs by up to 40 percent by allowing the re-importation of prescription drugs from foreign countries.
Under Obama's plan, he'd lower the federal poverty line which would make Perez eligible to receive medicaid with a zero or small co-pay. Last year, Perez made $12,000. Also, Obama's plan would allow the government to negotiate with drug companies for a lower price which would help reduce Perez's prescription cost.
Obama's plan also supports re-importation of drugs to help rein in rising costs, reports Pitts.
But critics caution neither is a silver bullet.
"If you're mandating or obliging people to purchase a policy that they cannot afford, it's not going to work in an area like this," says Jose Pagan, an economics professor at the University of Texas-Pan American. "People will always have the option of going to Mexico to get healthcare."
"People" like Rosie Perez.
"I can get health insurance from a private agency which will cost me $389 a month," she says. "I would say I bring in about $400 a month working now."