Ouch... 698k na ang Matrix... ouch!
Personally, five in the family, most subcompacts (Vios, Getz, Picanto, City, etc) will be kinda small if you're carrying baby stuff. Put a proper child seat in the middle of the back for your baby and the two passengers sitting beside it will be squashed up against the windows!
Bring your family when you go shopping, and, ridiculous as this may sound, bring your stroller-child seat (you can get a decent stroller-child seat combo for 7k) to see if it fits.
I usually carry four people + 1 baby + tons of baby items (crib, stroller, diapers, sterilizer, etc...), and we just fit
exactly in my four door compact sedan (Lynx). I don't think I could do the same thing in a subcompact, unless it was a new Honda City (huge 500 liter trunk, you can carry two dead bodies in there... oops, did I just say that?

).
The Suzuki APV has lots of space, there's a cheap version (under 600k), and it's good looking. Only issue is fuel consumption in the Metro, between 7-8 km/l (10 km/l+ on highway), because it's a 1.6 liter gas engine carrying a tall body. Suffice to say, don't get an automatic. If it came in diesel, it'd be perfect. If the slightly high consumption doesn't bother you, this is a great family commuter... cute, practical and fun.
The Matrix is probably the best fit for you, brand new. It's still priced reasonably, and offers compact car space in a subcompact footprint. Tipid sa diesel, and your kids will love the panoramic windows.
The Getz is cute, but kinda tight for five... try it out, though, if you fit, go ahead and get it. I want one myself, but it's not a practical size for me.
I've heard no bad news from Picanto, Getz and Matrix owners so far... nor Vios or Altis owners. You could probably get a
secondhand Altis within your budget that will do everything you need, and won't cost a lot in fuel or maintenance.
City/Jazz? Expensive. And before anyone comes in with the lemon complaint, let me just say: inspect the unit very carefully before buying it, to avoid trim issues. In terms of engine/transmission, though, these are the
best gas-powered economy cars you can buy... and the Jazz is lots of fun.
You might want to wait and look at
the Toyota Avanza. Seats seven, though the third row is kinda small. It's gasoline only, but Toyota will be releasing 1.3 liter versions (should get 9-10 km/l in the city). They'll have 1.3 units within your budget, but there might be a long waiting list when it comes out.
RE: BMW or bigger cars secondhand? Buy a big car, spend big money in maintenance (been there, done that). Okay if you're an enthusiast or a car-lover, but if you're using this as a family-mobile, practicality first.