Some Americans are moving their loved ones to Mexico, where an assisted living facility is cheaper. Westend61/Getty Images Long-term elder care in the US can cost 5-figures a month. Some families are moving to Mexico for cheaper options. Some Americans are moving their loved ones to Mexico, where an assisted living facility is cheaper. Westend61/Getty Images It costs about $10,000 a month to care for Richard Johnson, an 85-year-old living in a New Jersey dementia facility for long-term care . It's a price tag his daughter, Rebecca, doesn't think he can sustain. "It's just brutal," Rebecca, a 56-year-old New Yorker, told Business Insider. Rebecca anticipates that her dad, who's otherwise healthy, will need care for another 10 years, given their family's history of longevity . She worries that his retirement savings won't last that long. Initially, after his dementia diagnosis in 2016, Richard was cared for by his wife, a former political science professor.…