Are you talking PPL or CPL?
There are all sorts of things to consider. One school could quote the time including ground exams and another could quote the flight school only? You need to ask what EXACTLY is included in each package.
Per hour, USA and Canada (plus other Commonwealth countries) will be cheaper but you need to look at the validity of each licence in another country.
I have it from hearsay that there are things taught in a JAA UK syllabus that are not taught under FAA, for example, engine off landings to the ground.
As for your last question? If money were no object, I would learn (as I am doing) to fly in the UK. Why? Because that's where I want to live and work.
Let's face it, whilst we don't get the extremes of weather that can be seen elsewhere in the world, we do get very localized weather. I was flying today in glorious sunshine with only a few scattered clouds at a height far higher than I would reach only to be told by ATC that there were thunderstorms a few miles away!
The advice I was given (and I think was good advice) was to train in the country in which you wish to work. You also have to consider visas and work permits.
Cheers
Whirls