You can usually find out the price on the very first page of any online school. Regarding the price, I want to give only one piece of advice. There is no need to buy the cheapest certificate, for 1 dollar.
There are different certificates based on time, 120 hours, 150 hours, and so on. I’ll say right away that the number of hours on your certificate doesn’t really affect anything. What is more important is the time required to complete the certificate. You need to know whether you can take the test without any restrictions or, for example, this course only allows you to complete one module per day. In the second case, you will spend much more time to obtain such a certificate.
When choosing a certificate, I advise everyone to be guided by three parameters: PRICE, TIME, COMPLEXITY.
One can only guess about the complexity. As they say, you won't know until you try. But you can always familiarize yourself with the course content and draw your own conclusions.