비트코인은 여전히 싸다고 할 수 있나요?

It depends on the investment horizon. If you're thinking long term, probably yes. Note that by "long-term" I mean 5-10 years, not a year. However, there is a high probability that this year or next you will be able to buy cheaper not only bitcoin, but generally all cryptocurrencies. In 2024, there will be another halving, i.e. the reduction of the reward for miners by half. Thus, fewer new bitcoins will enter the market. So far, each time its price has increased shortly after halving, so taking into account the growing interest in this market, investments made by institutional players and the decreasing supply (some bitcoins have already been irretrievably lost and in the future there will also be cases of losing keys to cryptocurrency wallets, sudden deaths of owners, etc., which will further reduce the available pool), it is almost certain that this will happen again. On the web you will find a lot of charts showing bitcoin price movements with the previous halvings marked, draw your own conclusions.

It's dirt cheap

If we assume that ATH has no constraints then yes. Some crypto propagators rely on the scale of the network, so if you assume so, adoption is at the beginning of the road. But I think that the growth will not be as dynamic and spectacular as in the last 13 years.

You asked on March 29, I answer on June 23 when 1 BTC oscillates around $ 20,000 - and now it's cheap :)

Is cheap. If you can afford it, it is safest to buy BTC for 5% of your income, for example, once a month. In this way, without much risk, you accumulate a currency that can pay back x100 or more in the future. Look at the BTC chart and you will understand what potential exists in it. In addition, Bitcoin cannot be printed like ordinary FIAT currencies and that is why it has such potential