Go for the alarm + powerlock set. Yung mga generic alarms (Cobra or Venom) mga 1.2k tapos yung 4-pc. powerlock set mga 1k. Dami naglipana sa Banawe or Autocentro sa Cubao.
Have you checked out sa Virtual Banawe section ng tsikot? I found ones as low as P1700 complete with power lock motors na. Im not too sure how good they are though.
My car's alarm is a cheap kind lang. Its a "Carbine" which I purchased and installed 11 years ago. It still works like new until now! Talo niya pa yata yung mga ibang bumili ng mga mamahaling brands at that time. Unfortunately, wala nang Carbine ngayon...
Anyway, with my experience with my alarm (being a long lasting cheap one), Im not so quick to dismiss the quality of cheaper alarm sets.