Donald Abbey net worth: Donald Abbey is an American real estate tycoon who has a net worth of $800 million dollars. Donald Abbey is based in California, where he runs the highly prestigious real estate development and investment firm, The Abbey Company. He founded the company in 1990, and it has since grown to oversee 64 properties, totaling 6 million square feet of space. It is considered to be one of the most successful real estate firms currently in operation. The Abbey Group employs over 80 real estate executives, and manages 1400 tenants across their various properties. Donald Abbey's personal portfolio included two massive mansions that he built to the tune of $200 million. Construction took 18 years. He made headlines in late 2012, when he decided to unload both properties, simultaneously, listing his 3,400 square foot, 8- acre estate in Bradbury, CA for $78.8 million, and his 24,000 square foot home in Flathead Lake, Montana for $78 million.