May I offer some answers...
1. if going through an 'agent' or doing online through multiple sites... the rates for any city on any island in the Philippines is often 2-20x the 'for locals' rates.
2. networking with 'honest, friendly' (i.e. who does not have an agenda or runs websites for profit about Philippines) expats who have lived in various cities for years, can yield a more sensible set of facts; for instance where in town to locate for safe/clean/aircon, etc. and so on.
3. From the two facts above, you may find some particular cities 'cost much less for Good clean apartments' than others. Manila, and other nearby cities are 'off' mostly as to getting 'nasty' for 'champaign' prices. HOWEVER.... there are cities that cost 'less than half, and a couple 1/3' the price of Manila.
4. The most important factors is not the 'look of the building or area'... but:
a. safe, a gated rental building is best.
b. clean and 'landlord safe'... meaning, sanitary while maybe not fancy.
c. aircon
d. good working toilet and shower, good water supply, good kitchen sink and good-working refrigerator are 'basics' that will save you MUCH. Even if you get a partly or no-furnished place, these are essential.
e. Non-flood areas. (note that some key but cheaper cities in the SW are 'mostly hurricane proof', but you still need to assure you're NOT in a city's flood zone.
f. cheaper but nice, comes with likely NOT being in city center, but 1km around that center.
g. partly or full furnished are issues; but again, settle for 'good stuff' not 'western fancy' and you'll be happy.
5. Now some pricing... okay.... let's start with #1 above:
a. if you want 'home like Mom's'... then sure thing, you'll find condos and places (high rises, etc.) at the 30,000 to 50,000 pesos rate (well over 400 USD a month), but oddly, some are a distance from nice things like shopping, theater, churches, etc. .... THESE are the most plentifully advertised ones when you search ONLINE through agencies.
b. You are correct, a local family will rent a 2br apartment for less than $100 a month.... it is common for them to rent for 1000 to 2000 pesos a month; but in 'slum areas. You have to understand, most locals do not own 600 dollar laptops, or airconditioning (aircon). ..... HOWEVER... we have some good news for you sir..
c. for those who have experience living in 'other nations' other than their home EU or N Amer. countries.... they report (several I've talked with) enjoying a 'semi western' nice clean place, with aircon of course, furnished, at the 9500 to 13500 peso ranges in 'non manila' cities. However, some find 'good safe furnished aircon places' in the cheapest cities, usually a 20-30 min walk from city center (or ride bikes or jeepsters).... as low as 5,000..... but the 'nice but low-averages' run in the 8,000 pesos a month range.
Summary,... if you are like me, and others, who don't blow our evenings hanging around expats, but enjoy the local families WITHOUT looking like walking ATMs.... then you Can live 'nicely, safely and comfortably' for at or under $200. USD a month for rent. Elect, water, phone, internet, etc....likely another 50-100 USD... and food, if you cook 'some at home', in the 200 range.
I love the local families, and my past years overseas saw me spending 100% of my time with locals, and relishing being invited to every cultural event, wedding or funeral... and more... peaceful funny times together without a dime spent!
Being more international and durable (like some mil. vets are), and blending in.. will cost you less stress and money. And... you'll start to 'enjoy' the simple things of a peaceful life and good true friendships!
keep in mind, you will not eat like you did... so adjust there too.. (i'm kicking the chocolate habit, and the baked sweets). adapt, and blend... enjoy, and grow yourself in a new satisfying way.
And there you have it... you can blow your life hanging around expats, enjoy the 'bitch sessions' and the 'drunken parties'...and blow well over $3,000 USD a month... or... you can choose to become an international gentleman, and not only have better memories, not want to leave, but spend under 1500...and likely for some long-termers, under 1000 a month...and still live 'well'.
your choice... dress, demand, and be spoiled....a walking ATM... and you'll blow more, and attract 'money flies'....
but.. go with 'good people' in a modest lifestyle... and you'll be valued for you, and make life long 'true friendships.. and who knows.. maybe you'll find that 'life long good wife'.. a girl not on the web, right there in the city you adopted as your own, and who's good families adopted you like a son!