The five-year warranty costs come out of Vauxhall's coffers...it's the dealer making the money out of the service. The cost depends on what that particular service entails...if it's a simple one, then it's expensive. If it's a very comprehensive one, it's fairish!
chrissa, it depends on what is involved in the 2nd service, probably not just an oil and filter change.
If I were her I would get a few quotes from some independent garages ( usually quite a lot cheaper than main dealers ), so long as the garage uses Vauxhall recommended parts and is VAT registered she will have no trouble with her warranty.
Do people realise that you do not have to use a dealer to keep up the warrantee? providing the family run garage uses the genuine parts the Warrantee holds, are people made of money?