If i am just a new investor in bitcoin having a price of 100,000$, i think i will only buy a small slice of it because i could not really afford to buy a whole of it. I am going to hold it, let it grow up higher and if the price is already right for me, then i will sell it right then.
On a normal day, you cannot buy more than what you cannot afford. If bitcoin is $100k or even more, it is few of the satoshis you can lay your hands on that you will still be able to buy in anyway, so I do not see how that is a serious thing to be assuming how much one would buy in such instance or not.
Apparently, just very few people would be able to afford to buy a whole bitcoin in such a scenario, but that being said, to see such a huge price, it would only be sustainable if it is driven by real demand and not just some mere speculations.