Organic Farming
Costa Rica uses 8 times as much pesticide as other Central and North American countries. They are also having trouble buying fertilizer. I think a small organic farm would be a good business. There is no certification or inspection process for organic but the existing farms have tours to convince distributors and consumers. Foreigners can start a business but they can’t work in it. Agricultural workers are easy to find and starting a business and hiring locals is a good way to establish residency.