Unfortunately this one sounds like a scam. But if you still want to contact the person behind the listing, press the Contact Property button at the bottom left of the photo. If they come back to you saying they are out of the country/city but encourage you to fill out an application and give a deposit, it is a scam. In that case, press the Report Error button and follow the instructions to report spam so noone else gets caught in the trap.
It will be difficult for you to find a 4BR rental anywhere near this rate. Best area to look will be very far west in the Sunset or more southward, or in Bayview/Hunter's Point, but I don't consider that a very safe neighborhood.
McGuire Real Estate