You’re right to some certain point, yeah if you go into investing in bitcoin with money you can’t stay without using for long you may end up regretting , in situation like this recent dip in market if you use such money like your house rent , school fee etc to invest the chances of you selling in loss is pretty high so avoid such .
When investing in bitcoin there are sometimes you need to be aggressive because if you continue to use only little percentage of your money , you will only slow things down like using $10 while you know you can increase it without it affecting you financially, like times like this with the market recent dips some folks tend to be more aggressive in their accumulation trying to make better use of any opportunity they got but without over doing it though which will speed up the pace and same time be in a safer side .
To build a good Bitcoin portfolio, in addition to buying regularly, it may be a good idea to buy a little more aggressively when the market is in dip. In this case, you should also have an idea of how much the investor's ability is. Even if there is an opportunity to buy at a low price, if the investor's financial situation is not stable, then it is definitely not logical to buy Bitcoin beyond his ability. If you have the ability, it is better to buy more, and if not, it is safer to buy within a certain amount. Those who are intelligent and prudent will definitely try to hold more by accepting the decline in the price of Bitcoin as an opportunity according to their ability. Those who can apply the strategies to hold Bitcoin correctly will be able to benefit more than others.
This can be achieved easily and without stress if the investor in question plans for it before hand, for example an investor who has $150 discretionary income weekly and decides to invest $100 into bitcoin comfortably while using the rest to build backup funds and as spare cash, it would be easier for this investor to DCA with $70 while he stacks the remaining $30 in anticipation of the dip, when the dip presents itself, the investor might choose to lump sum with accumulated funds, or increase his aggressiveness with already stacked funds, let's say increase his weekly purchases by 50% ($150 now) from already stacked funds and still maintain his comfortable level of aggressiveness from his weekly discretionary income and being more aggressive from funds already prepared for the dip.
If peradventure he doesn't prepare for it and suddenly starts investing all his discretionary income into bitcoin, that might be classified as being over aggressive and might tend to discomfort the investor in some kinds of ways that can be detrimental to his accumulation journey.