New Mexico is about 510 times bigger than Saint Lucia.

Saint Lucia is approximately 616 sq km, while New Mexico is approximately 314,310 sq km, making New Mexico 50,924% larger than Saint Lucia. Meanwhile, the population of Saint Lucia is ~167,122 people (1.9 million more people live in New Mexico).
Tip: This to-scale comparison of Saint Lucia vs. New Mexico uses the Mercator projection, which distorts the size of regions near the poles.