Not enough for what? To become a millionaire?

Everyone uses the bitcoin differently: for some it is the road to wealth, and for others it is the road out of poverty.

Everyone invests in a bitcoin based on their capabilities. There is little honor in reproaching others for such modest investments.

This is quite enough to get started. OP doesn't claim that this will be his first and last investment in the ditcoin. If he does this every day, then in just 1 month the investment will be ~$150, and in a year - already ~$1800. Even if he double or triple this amount of money over, say, 5 years, this will already be a good indicator.

I am inclined to believe that the first investment should be small, enough to understand how everything works here. Nothing prevents from repeating the purchase of bitcoin for a higher amount of money, right?

It's good to have the ability to see the future and I would also like to know how much a bitcoin will cost "before the next significant bull run ended".