Any travel ideas for Valentine's day? my budget is 3500 php, thinking of beach,spa with promo's 4 couples

Any good places to visit here in the Philippines? where I and my bf can enjoy even on a tight budget?

3500php will take you nowhere,
35000 php is just enough to pay your taxi or bus fare.

It depends on where you are coming from. But that's really a tight budget for two. There are many pool resorts in Laguna where you only have to pay the entrance fee for a day's visit. Or if you like to stay overnight, maybe you can try City of Springs in Los Baños. Here's their website: http://www.splashmountain.com/3/rates.html

If you can raise a bit more money, maybe you can try Villa Escudero in San Pablo City. It's not a beach resort but if you like something different (e.g. a cultural rendesvouz which can also be romantic) it's worth a visit. You can dine (buffet meal) on tables set on a man-made waterfall, ride a buffalo-drawn cart while being serenaded, ride a bamboo raft on a lake, watch a cultural presentation, etc. Here's the website: http://www.villaescudero.com/pages/VILLARATES.htm