The idea of something being cheap is a relative concept. Ask yourself, when bitcoin was cheap, what did you do? Another thing to consider is that Bitcoin is still cheap. What makes you think that it is expensive at the moment? Your own worldview that something that was cheaper is now expensive?
Think about it for a minute. Bitcoin has gone from nothing to $15,000 in 12 years. No one was watching it for most of that time, and they used to give it away for free. Not many people wanted it when it was free, but today, people will spend hundreds of millions of dollars to buy it.
Do you think it is expensive today?
It is common for people to think that there is a balance in nature, and somehow this extends to financial assets. However, this is a very foolish way to view financial instruments. Try to spend Argentine Pesos that were created in the 1970s. You can't.
Worthless currency just keeps getting cheaper, and something valuable continues to gain. Bitcoin is going up in value, this isn't an assertion, it is a fact. You may or may not like that. But it is true. Unless today is that absolute top of the Bitcoin market, it is still cheap.