Financing for a non resident through a bank is still kind of complicated because of the bureaucracy. The interest rate is between 8.5% and 12% in a US$ loan. Most of the deals in real estate are cash deals or financed by the Owner or Seller, usually very short- term from 6 months up to 3 years with high down payments (like 30%-50%).
Sometimes the buyer can get better rates and faster approval (or easier approval) using a first or second mortgage in their home country on property they have there, then the cash can be used for buying property in Costa Rica.
Once in a while we have private lenders offering their services. We will be glad to introduce you to them.