Main rule for all people, whether wealthy or not, is that one should invest only extra money, which is money they do not need, as prices of Bitcoin change much.
In terms of strategy, best way is DCA and it is suitable to new investors. One of biggest mistakes is to wait until it goes down, since you will likely miss out on buying chances as you wait until it goes down and it might never go down.
This point of yours cannot be the main rule for all people when it comes to running an investment because not everyone should just invest extra money, it's up to everyone, it's necessary to balance our investments and savings, However, after accumulating an emergency fund, everyone may be able to consider investing additional money. You are right that in terms of strategy, the best way is DCA because this specific strategy eliminates the misconception of entering the market at the right time, In fact, the point is that this method simplifies the difficult task that arises for new investors when it comes to entering and exiting the market at the right time.
Rich people are at advantage as they can invest more extra money leading in greater returns. But, greatest rule is that all people must invest only what they can afford to lose, and therefore, steady, smart investing will give results based on financial level of an individual.
The Bitcoin market is the same for everyone, rich or poor, but what matters is how much money you can comfortably withdraw from your spendable funds because the biggest rule in investing is, You can be disciplined with your BTC purchases by using the money you have left over as savings for entertainment or future plans after all expenses are met.
