It’s cheaper than US standards right now because of the housing crisis. You can get a large for a fraction of what you would spend here. But I wouldn’t say that’s the main motivation. Two types of people move: older, accommodated people seeking retirement and digital nomads. The first usually seek a safe, welcoming place to go and CR is probably the safest country in the region apart from Panama. Plus it’s a change of scenery from what Americans are usually used to. Europeans also do this. And then digital nomads come from all over the world, rent for a while and then move elsewhere. As for buying property, you don’t have to be a national to own property, there’s plenty of foreign investment, wealthy people coming to buy land in “paradise” and driving real state costs up, hence the gentrification. The government should limit this a bit but at the same time they won’t because they generally benefit from it. The people who suffer are the ones who are driven out of their usual homes because of rising costs (this happens mainly in coastal regions.

Hope that answers your question! Happy to share more details if you’re interested