The cost of public health insurance is based on your income. If you have a high income, your health insurance is more expensive.
The Höchstbeitrag is the maximum cost for public health insurance. If you earn more than than €66,150 per month, the price does not go higher. The minimum cost is called the Mindestbeitrag.
The Höchstbeitrag for employees is €600 per month. The Höchstbeitrag for self-employed people is €1,200 per month.
There is no Höchstbeitrag for private health insurance, because the price is not based on your income.