No one in their right mind would want them (airframes are well and truly shagged), and I very much doubt (and I mean absolutely no offence by this) that the Phillipines would have the capability to operate and sustain them in any meaningful fashion. Australia was struggling very much with this in the last few years, to the point of requiring an interim strike aircraft (Super Hornet) be purchased in order to replace them.
Abe would be able to give you a far more specific answer, but in short, the airframes are old, their systems have been pushed as far as they will go, they are complex and they are extremely maintenance-intensive. The support costs and requirements alone would be staggering, and if the RAAF struggle with it then I don't think the Phillipines are going to do any better (and again, I mean no offence, but in terms of resources, fast-jet experience and qualified support personnel the Phillipines would really be working from a disadvantage).
There are far, far better options available. for ANY air force.
EDIT: In addition to the above, I believe there would be an issue with re-selling the F-111Cs, and it's my understanding that all our C airframes with the exception of one or two museum pieces will be returned to the US for destruction. If I remember correctly this has to do with the F-111C's role in the USAF as a nuclear-capable platform (though my memory is hazy and I'm happy to stand corrected on that).