Love Costa Rican coffee, and go to San Jose about once every 6 weeks on business.
There is an Auto Mercado supermarket about 4 miles from the airport using the road past the San Jose Marriott to Santa Ana which has all the brands.
Recently I have started buying Cafe Britt online at cafebritt.com and price is about the same or less (depending on the deal) than what you'd pay in San Jose. You can also ship large quantities most times for free. Service is excellent, and they deliver to me in Ohio (from Miami) in about 3-4 days.