Ilovecheese
I can understand wanting to live in another country because you prefer their values and culture to our own. But just to hold on to a few quid?
Yes, leaving friends and family, a culture you're part of, social networks etc behind for money is an alien concept to me. I can understand people leaving war zones or oppressive regimes, and leaving countries where poverty is the norm; but the sort of economic migrancy that means fleeing tax bills just doesn't make sense.
Wealth is always relative, so even if someone is so driven by money that they would give up all of the above, their relative position will be the same as if they stayed put. If they earn more than the people around them they will be better off than their neighbours regardless of the taxes they pay, and after essentials are covered relatively small disparities in disposable income make a big difference to spending power. Moving to somewhere with lower taxes will mean that everyone else pays less, too, so they will still be on the same income, and have the same status and spending power as their peers, which will usually put them on pretty much the same place on the social hierarchy as here.