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.
Many normies when they are new to bitcoin (or even investing for that matter), will erroneously come to the mistake that they have to GO BIG or GO HOME, so it can be quite difficult for them to internalize the idea of DCA... so they have tendencies to want to front load their investment, even prior to their getting used to investing into bitcoin and before they have really figured out how they were going to go about it.
So even if they might say that they are ready for either up or down prices, they might end up not really being prepared because they ended up over-investing in light of their own mental preparedness.
I understand that no one is comfortable losing money, even if they ONLY put in $10, so there can be some difficulties for any of us to get over our loss aversion sensations and to figure out a position size and even an investing approach that may well allow us to continue to invest (such as DCA) for at least 4 years before really starting to potentially strategizing around price, and really, sometimes there may be some needs to invest 10-15 years or longer before starting to worry about price, especially if the amount invested might even be less than 10% of their income/expenses...so it can really take a long time to build an investment portfolio that might cover 1-2 years or longer of expenses, especially if the investment amounts are not very high.