There will certainly be a huge difference in their investment strategies. The person who chose to invest $100 weekly would focus more on the DCA strategy,
I still think that we are making different points, because in my hypothetical, I am presuming he does not have that $100 per week in advance, and he is only able to invest $100 per week as it comes in. His only other option would be to just let the $100 per week to pile up in order to buy on dip (if there is a dip), and if there is not a dip, he is risking that he might have to buy BTC at higher prices rather than if he were to just buy each week as the $100 comes available.
This point is actually not too wrong but in the end, won't this make the situation a little complicated for yourself, especially for beginners who are only trying to predict roughly because they are definitely still not too familiar with some techniques in analysis or technical analysis so they are like waiting for things that are not too certain when the decline occurs and this could actually make them not make purchases that should be made because it is not easy to change the view when assuming and hoping that prices will fall to being full of risk by buying without thinking about prices.
Not that bitcoin cannot go down because in the end price fluctuations will certainly always exist but on the other hand we must be aware that guessing without a clear situation because they (beginners) only roughly guess that bitcoin will go down is actually in my opinion complicating themselves so it would be more worth it if they did make a decision from the start by buying bitcoin directly without having to wait for dip when they are able to do so.