Central locking for a sedan is typically Php1,500. That's a four door set up already. I'm expecting two doors to be less expensive.

The keyless entry/alarm/anti-theft system will cost around Php1,900. That would be a Cobra, Venom, Police or other Taiwan brand system.

The price of a keyless entry vs. that of a full anti-theft system (car alarm with ignition kill) is not that far off. I suggest just get an alarm. It has a switch in case you want it to function only as a keyless entry system while still being able to offer vehicle protection when in anti-theft mode.