OAKLAND -- A San Francisco man who set up a deal through a Craigslist ad to buy some iPads in Oakland's Redwood Heights neighborhood Monday night was instead beaten and robbed of cash and his Mercedes-Benz, police said Wednesday.

The incident was reported about 8:13 p.m. Monday in the 3500 block of Jordan Road, a quiet residential area.

The 20-year-old man told police he spotted some iPads for sale on Craigslist and a man responded and they set up a meeting at the Oakland site.

The man was standing by his car talking to the so-called iPad seller when a gunman walked up, pushed him to the ground, hit him in the head and demanded his money. The man lost more than $1,000 and also the Mercedes, which contained several cell phones, including his own.

The last thing the victim saw was the 2001 Mercedes driving away followed by a gold Lexus. He could not tell which car was driven by the gunman and which by the so-called seller who police said set up the robbery.

Police and Crime Stoppers of Oakland are offering up to $2,500 in reward money for information leading to the arrest of the robbers. Anyone with information may call police at 510-238-3326.

The robbery and carjacking is one of many investigated by police that have involved Craigslist ads. Police caution those involved in Craigslist deals to be extremely careful and insist transactions happen in public places, even at the police department if there is any concern, and to not be alone and to avoid actual cash transactions especially if you are a buyer.