Bitcoin should be bought and held regularly based on how much more profit it will make in the long run.
In 2016, 1 Bitcoin could be bought for $400, now it costs $112K+ to buy a Bitcoin. In the last 10 years, the price of Bitcoin has increased by hundreds of times. Now it is not possible to buy a whole Bitcoin with less money than before. But if we calculate the valuation of Bitcoin in the future, then if someone follows DCA for 4 to 10 years with less money and cannot buy the whole 1 Bitcoin, there is no problem. Because after 10 years, the value of every Satoshi he has will be several times higher. So even if he cannot buy a whole Bitcoin or a whole Bitcoin, there is no problem because after a long time, the profit will be many times higher than the investment.
None of us can ever see or say the future. So no one knows what the price of Bitcoin will be in the future. So instead of investing on leverage, first set a goal of how many Bitcoins you are willing to deposit in your portfolio. If you invest like that, you might get something good. As you said, if you invest on leverage, if you hold on to $300 and expect to get 50,000 from it 10 years from now, if you do and the price of Bitcoin does not increase as expected, then you may be disappointed and your faith in Bitcoin may be lost.
So first you need to set a goal of how many or how much money you will save in Bitcoin in your portfolio. If you go ahead like that, it will be much better for you.