First you must owe a house. Don't buy it with financial. The interests are too damn high. Look for newspapers, the best is Diario Extra.
Most advertisers are low-middle classes.
You need to check how long they had been financial it. Under 7 million you only pay around 8 thousand colones a year includ the trash picked up. If you pay the whole year before 30 of March. If you had bought your lot very expensive and your lawyer didn't help you to low the report. You need to change your lawyer right away.