Hi Ronn,
Most expats choose to send their kids to private schools in Costa Rica. There are all sorts of schools, from American-style schools on U.S. curriculum to homeschool style places fun by parents to Montessori to small neighborhood private schools with mostly Ticos as students. Some are taught mostly in English, some are completely bilingual. Tuitions range widely, from $4k to $11k tuition per year for the top schools accredited in the U.S. so credits transfer easily to $200 a month for smaller schools accredited only in CR.
If you go to this page and scroll down, you’ll see a detailed breakdown of education and listings for schools around the country:
https://internationalliving.com/country_clubs/costa-rica/insider-tips/