I seem to recall there was a bunch of a half dozen British guys that did exactly this down in New Zealand, when I was learning to fly at the school across the airfield. They'd all chipped in a couple thousand quid, bought a nice C172 and then went and flew all their hour building in it before selling it on.
The cost of flying a privately owned aircraft down there, for something like a C172 or PA28 should work out at no more than about $60 NZ per hour, i.e. a bit less than £20. There are of course plenty of existing aircraft syndicates that you could buy into, if you don't want the hassle of owning a whole plane yourself.
Of course if you really want to be enterprising and cash in on the current outstanding Brit-downunder exchange rates, you could do what my pal did last year, bought shares in a Beech Duchess when he trained for his kiwi instrument rating, I seem to recall he was paying $140 kiwi per hour wet for the thing ... that's about £45 at the current rate of exchange, not bad by anyone's standards. Needless to say if you were to do your hour building in one of those, it would certainly make your CV stand out amongst the rest of the 200 hour people
I'm heading back home for a holiday myself for a couple of months in the new year, and I'm already taking one pal with me to do some cheap and cheerful hour building. I'm qualified as a JAA and NZ instructor and I'm more than happy to offer advice or assistance for anyone thinking of heading down thataway, just pop me an email.