$1,000 is way too much. You should be looking more in the range of $400-$600.

I'm in the US, but the exchange rate is very close to 1:1.

For OEM parts:
$62 for the belt
$83 for the waterpump
$3 for the gasket
$25 idler pulley
$20 tensioner
-------
So about $200 for a full service

Add $50 for serpentine belt change while you're in there.

So you have $250 in parts, obviously this doesn't include the dealer markup. I'm guessing it should take a GM tech 2-3 hours to complete the service properly, so... like $300 in labor? that's $550 on the high end. Where's the extra $450 going?