Hi William, The actual property in an area of San Diego called Carmel Valley which is adjacent to Del Mar and you will not find a rental for $900/mo in Carmel Valley. This is a great community with San Diego's top rated schools. This particular property was for rent in December and it rented for $4,600.00 per month. It is a big house, almost 3,400 square feet.
There are a lot of scammers on Trulia, and they make up their own posts here on Trulia with unrealistic numbers and are asking people to send them money. Never send or give money to people without seeing the property first and signing an agreement or an application to rent, and meeting the owner or their agent in person.
Best of luck to you.
Burke Real Estate Consultants