You're right Steve, this is question that gets asked plenty of times. Probably because it's too difficult to answer for the satisfaction of everyone.

I'd like give my thinking, if I may, solely based on my plan of how I would want to live my retirement life in Philippines.

I believe I could live very cheaply if I wanted to or needed to. Living a simple life and just relaxing.....
But for me personally without having an array of options for doing stuff that makes me happy, keeps my brain working and keeps me active I'd fear boredom and the effects of that on my outlook and my health.

So in addition to simple living, relaxing and eating frugally I have to consider the costs of living a life I want and keeping 'killer boredom' away. Means different things to different people, but for me I want to have an interesting and fulfilling retirement life and for many of my ideas that's going to cost extra.

So whether it's the addional costs for acceptable internet access, or the costs of socialising, travelling as a tourist, Island hopping, sports activities, water activities or just family picnics etc...I'd have to include that.
If I decide I need to have my own transportation then I'll include that too.

I hope to be able to maintain a living cost budget that's not so restrictive that I'd eventually end up bored. And sad. And miserable.
I can easily achieve that in UK

I'm not good at explaining it but hopefully the overall concept will be understandable.

If I can live the life I'd like on £500 great.
If it's going to take £1000 -£1500 that's what it's going take. Others might see that as wasting money but it's an essential living cost to me

If living in UK or Japan or Malaysia offers me a better 'deal' then that's where I'll be.
I can't imagine such fantastic opportunities as a retiree in UK but who knows what the future holds.
I can go ten-pin bowling everyday in Philippines for the same cost as an evening session her in UK
I can have a boat and go fishing whenever the weather allows. Oh and the wife of course

I'm getting excited again now