As Yiannis has said, £300 all in sounds about right. I had a ring round out of curiosity, Not sure exactly as it was back in May but I think Renault quoted me around the £320-£340 mark, Local specialist was a fair bit cheaper. Always get my local garage to do mine though as I know/trust the guy there and the price is always good, think I ended up paying about half of what Renault quoted and that was with parts I asked for minus the air filter (I have a k&n fitted)
Is it worth having a interim service after 6 months ? I've only covered 3k since my major service in May ?