Colombia is a great place to look out for this types of properties. The 80´s and 90´s left a bunch of stupidly big houses confiscated by the government. They usually come out for sale though the state department for a fraction of the real price. Yes, they are quite old and some of them have been scavanged by treasure hunters, but the investment needed for a revamp is meaningless compared to the real price. They would range from 300k up to a mill or two.