Yes, replacing the Starter battery the minute it showed signs of having an issue, would have saved a lot of money.
I think he paid the Dealer nearly £800, new Bosch Alternator unit, Lucas Starter battery with fitting and VAT. He still had to replace the Starter battery anyway.
Because it was all so rushed, he was on his way to us and then on to the Ferry for France, he didn't get any say on the Starter battery that was fitted, which turned out to be low quality and was nearly a year old according to the dates.
I wouldn't be surprised if the poor replacement battery meant he went full circle inside 3 years.
So it isn't just about the jump start itself risking the habitation electrics, the web page documents the reasons why there is a risk to the Alternator following the jump start. Sometimes immediately, sometimes down the road.
Unless the radio or lights have run a new battery flat, the battery has usually discharged because of an internal failing, which along with it being very dead may load up any charging system massively.
The web page documents better, and cheaper (in my opinion) ways than the traditional approach of jump starting a flat battery.