Investing in Bitcoin may not be expensive for those who have money but Bitcoin is very expensive for those who don't have money. But it is wise to invest even if the cost is high because if you want to invest in Bitcoin you have to buy a few digits and in this case you don't have to invest in a Bitcoin because whoever has the ability will invest in Bitcoin according to that ability.
Yes, if you see it that way I understand you, but if you apply the DCA method it is another thing, so if so you can buy fractions of btc every day or every two days as you want , the important thing is that you accumulate constantly , it is the only way you can get bitcoin and that it can function as having 1 bitcoin but in the long or very long term. So there are options to get BTC, you just have to have the ability to gradually buy the fraction of btc that you want but with great regularity having as a goal to make 1 btc , so don't worry, you haven't missed the train.