Travel from Britain to Austria by car and ferry, advice needed please.

Hi, I am a carer for my son and wish to hear from people who have experience travelling to Europe preferably by car and ferry. We had some private firm in mind, but their initial quote was increased every time we communicated, with toll charges, extras for travel, etc.pushing up the price. I don't drive, never have done, I'm afraid, otherwise we could plan everything ourselves. We know the route, we know places to stay overnight, so it could be quite straightforward. Please let me know of any organisation or private firm who might be able to help. Thank you.