Probably not as much as you would think. Money can buy you access to cutting-edge medical treatment... but not safe or effective cutting-edge medical treatment. Almost all new treatments don't work or have more drawbacks than benefit, that's why it's called research - and billionaires get access to the results of the big clinical trials at about the same time as everyone else.
One possible difference is his access to tailored research and treatment.
When Finnish geneticist Leena Peltonen-Palotie was diagnosed with rare sarcoma in 2008, her colleagues started big project to save her life. Her cancer became the "worlds most studied cancer" for a short period. They sequenced her genes and used large screening robot to test tens of thousands combinations of different drugs against tissue samples taken from her.
They actually fond a cure for the sarcoma she was diagnosed with, but the cancer had already mutated into a form that did not respond to the treatment and she died two years later 2002. I believe this might have been the first ever for this kind of large scale tailored cancer research. Weirdly enough I can't find any mention of this research effort in English speaking magazines.
"They actually fond a cure for the sarcoma she was diagnosed with, but the cancer had already mutated into a form that did not respond to the treatment and she died two years later 2002"
One could also cite Steve Jobs. Despite heroic measures, his delay doomed him.
(To expand a little bit on this: the Gompertz curve means that even if a 85yo billionaire contracts some cancer and is able to buy a cure no one else can which isn't useless or iatrogenic, he is going to die very soon anyway as the annual mortality risk increases exponentially. This is what is behind those surprising observations like 'curing all cancer would only add a few years to the average life expectancy' - curing cancer just means that you die of dementia, Alzheimers, a heart attack or something else a year or two later.)
Steve Jobs had good prognosis but he delayed the surgery almost a year and relied on 'alternative medicine'. Even with late start he still lived eight years after the diagnosis when doctors used all tricks money can buy.
> he is going to die very soon anyway
This is true. People close to 90 are one flu and pneumonia away from death.
