In the article: Americans looking to Mexico for real estate [Bankrate.com]  1.5 million Americans own real estate there. Values have tripled in the past 5 years, outpacing the US housing market.
However, foreign buyers pay premiums such as 30% down or financing through Mexican banks at 15% or more. Some US banks are starting to offer financing but the laws are different in Mexico providing more risk.
“Development was spurred by skyrocketing real estate prices in the USA [USAToday]  and changes to Mexican laws in the wake of the 1994 North American Free Trade Agreement (NAFTA) that encourage foreign investment and make purchasing beachfront land easier.”
In Baja, a 1500 SqFt house costs in the mid-$200k range.
I would suspect that demand for properties across the border would ease if demand in the US eases. Although the financing costs are higher in Mexico, the actual values are far lower [WSJ]  which is a lure for US buyers.