How much is indemnity insurance for psychologists?

It depends in which state or country you will practice, the level of cover you seek, the sort of people you are counselling, past claims, expertise and how long you've had the practice.

You'd be best asking for quotes directly from insurance companies.
Of course check online reviews to determine whether the most appealing quote from a company is good value for money.

It depends on where you practice and the type of practice you have. I assume you are referring to professional liability; this varies dramatically, based on the litigiousness of your state.