If it is listed on the MLS in Southern California and did not go pending in the first hour, it is NOT a candidate for a flip. And no, you can't deal with the seller directly. You saw the listing because the seller signed a listing contract with the listing agent and that agent posted it to the MLS and then to other sites.
There are a few sellers that will sell low to avoid listing with an agent, but they are very rare. Most FSBO's think their property is worth more than the agents suggested as a list price. Since they are smarter than the agents, they try to sell it themselves.
If you spend a lot of money to buy lists and send out postcards, you are wasting your time and money. Those lists are bought by a lot of people with the same idea. I get 20 pieces of mail a week soliciting me as an out of state seller. Straight to the recycle bin they go,