Remember Miranda rights? 'If you cannot afford an attorney, one will be appointed for you'? Do you assume that is free of cost?
First off, you have to file an application for a public defender and that can range from $10 (NM) to $400 (Ark,).
In some areas, if you plead or are found guilty there is an additional fee. Think about that one. These fees are used to pay public defenders, and if you have a public defender and are found guilty, the fees increase.
I have only had experience on one felony trial where the young man had a public defender, and he would have been better off defending himself. At the time, I thought he got what he paid for – as it turns out, he did not.
This question is in the General Section. Responses must be helpful and on-topic.