There are some rumours on this forum that Alfa upgraded the Variator so they don't fail as often.
My cam belt change is due (3 years and 15K miles since the last one) and the Variator was changed last time around.
I'd rather not fork out 90 quid on another one if it's not needed. In fact I'd rather get my hands dirty and change the belts myself but when it comes to changing the Variator there are quite a lot of stories about it being a complete bugger to remove so I'd prefer to leave it alone!
15k miles is nothing - I'd leave it in if its not got the death rattle. Oil changes, oil flushes and using the rev range to re-fill the variator & solenoid with oil every time the car is run is the key to long life.
I suspect that variators have been improved, both from my own experience & from the drop in the number of "my car sounds like a diesel" threads on this forum. My early 2005 147 had done around 55,000 miles when I sold it, to the best of my knowledge on the original variator, with never a hint of any rattle.
I believe my variator is the original at 101k. The car had it's first cambelt ay 69k by previous owner. I have the receipt from Monza Sport and there is no variator listed. It makes a rattle for a second or two on start up and then goes away - not the death rattle! I've heard worse at half that mileage. It only made the slightest hint of a noise at 84k when I bought it. (2000 146Ti but same engine)