A wedding in the phils is better value, but that doesn't necessarily mean that it would be cheaper. Big wedding in the Phils with loads (and it could be loads...) of family and friends could cost more than small wedding in the UK as you can get married very cheaply in the UK.
But getting married in the Philippines would require you to make an extra trip to the Philippines which is likely to cost you at at least £500 just in travelling costs.
FLR is the easiest to apply for, and even with a spouse visa you need to start collecting evidence for ILR immediately anyway.
But getting married in the Philippines relies on you making a longish (at least 2 weeks?) trip to the Philippines which depending on work could delay you for longer. Maybe it's just me but when my wife (then my fiancee) came to the UK which was her first visit to another country (especially as it was winter...) I wouldn't have wanted her to work immediately even if she was allowed to.
Swings and roundabouts....