Speculations will remain as speculations unless proven or disproven otherwise. Despite this, a lot of people are believing that bitcoin will indeed reach 100k this year or Q1 of next year which is very possible considering the past year's performance of bitcoin. Still, I would like to place a disclaimer for you indicating the fact that bitcoin isn't a get-rich-quick scheme, nor is it a get-rich-guaranteed scheme of some sorts, so be sure to only invest what you can afford to lose, otherwise the detriments will be much worse for you than what you may have anticipated.
One of the thoughts that will keep you cool in any situation if you want to buy bitcoins at any price is to think of your investment as savings. I've read several people saying the same thing probably for the same reason and I think it's the right way for you to do it.
The thing that support this thinking is that you are pretty sure of the potential for bitcoin in the future to hit $100K. Currently the bitcoin price is trading at $44K or lower than its last ATH so it is still possible to buy bitcoin and hope the ATH will rise again. Previously, if people who bought bitcoin at the peak price of late 2017 did not buy more bitcoin during the down, then they would have to wait and store their bitcoin for 3 years to cover the losses incurred as a result of the decline. There is a possibility that the losses will be covered faster if at the time of the price down they buy a lot, but if not then it will take 3 years to recover the losses.
The same thing could happen to you right now. If the price target you want to reach doesn't happen after you buy, then it will take you longer to see the $100K price come true.
Would work if you are very willing to have your investments be sitting in your wallet in 2-4 years untouched, regardless of the market's movement and behavior within that timeframe. Some people will be willing to do that but for those who cannot afford losing their investments for reasons, might as well diversify your portfolios so you don't lose all your money in one basket when worse comes to worst.