Well.., of course the standard of length you guys have over there is about 9" overall length, but the quality of those pieces made in the Barrios surrounding larger Batangas cities is somehwat questionable unless you get to know some of the local makers and get to "hand pick".
Generally, you will find the quality of the american made Balis much better, and without an extended "break-in" period as with many of the handmades sold to tourists in your country. I do have some very nice pieces made in your country, but they are getting few and far between in honesty. It seems like most of the younger people that would have carried on the tradition of making Balisongs have moved to the larger cities in search of more profitable job opportunites.
Most of our Balisongs over here are in the vincinity of 4 inches in blade length, but we have a wide variety of 3" blades, and some 5" and you see over there.
If you are just starting out.., I would certainly go with Benchmade Balisongs, so you can have a clear perspective on what a really wellmade piece is like. From there..., there are custom makers, and prices start to get prohibitive, but certainly well worth the money if you become really interested.
Hope this helps....
"Hunters seek what they [WANT].., Seekers hunt what they [NEED]"