Some people always think bitcoin is expensive but it is not. For instance if 1 bitcoin is = $10,000 we will say it is too expensive and when we look at the price in next two years it can be double($20,000-$30,000) and we realize that bitcoin at $10,000 was very cheap and something very affordable. The future will always make us understand that bitcoin is not expensive, we only miss expensive opportunities that we won't be able to get back.
Well suppose Bitcoin is expensive but in that case no one is forcing you to invest in Bitcoin rather invest as much as you can in Bitcoin as per your ability. One should not invest one bitcoin but invest and hold 0.002 bitcoin amount. No matter how expensive Bitcoin is, if you want to invest, you will invest no matter how much the price rises.