I had mine done a few weeks ago at just under 85,000 miles, or about 135,000 kms. I wouldn't tell you to leave yours that long, so you'll have to make your own mind up when you want to do it. It had started to make a little noise at lower engine speeds so I took it to a FIAT specialist south of Manchester and it cost around £300 or €450 for parts and labour. But that might not be much use to you.
Any main dealer will cost more than a specialist so it might be worth trying forums with a lot of members from your own country. You could also look at Vauxhall/Opel forums as the (basically) the same engine is used in Corsas and Astras.