While it's true that many patients are almost being tested and even treated for free, you can't deny the fact that some people are being charged a fortune worth $3k-$4k just to have a COVID-19 test conducted on them and the treatment bills are a surprise package if you are found with and get your treatment started for this virus.
Can you share some sources here about that?
For testing suspected patients, it's always free of charge as it's a mandatory and necessary thing to do by each country's health department to ensure that as much as possible they will able to lock down all infected people in an isolated area to prevent further virus spread.
If that's true that people will pay for a test, I doubt many will undergo with it as the price you mentioned is insane and not afford by anyone.