The median price for houses in San Juan, Puerto Rico is nearly $1 million.Oscar Gutierrez/Getty ImagesPuerto Rico is becoming a popular destination for mainland Americans seeking tax breaks.However, an influx of wealth is driving up housing costs.Young Puerto Rican professionals are being forced to seek opportunities abroad.Finding good jobs and affordable housing is often a challenge for young Americans living in the 50 states, and that issue is stretching to Puerto Rico.Puerto Rico is becoming an increasingly popular destination for mainland Americans looking to relocate for tax purposes without giving up their US citizenship.