A good rule of thumb when dealing with settlements is to start the negotiation by demanding three times the cost of the medical bills. In this case, that would be starting at $225,000. Depending on the facts of the case, that means the settlement should be between $75,000 and $225,000.
Debt is settled for a percentage, depending on many considerations. There is no standard settlement rate for debt. It can range from 80% to 10%. It's up to the creditor to determine the write off, based on the age of the debt, interest, penalties, the situation, etc. Negotiation with the debtor is also an issue.
A settlement can be anything both parties are willing to agree to. There is no set percentage or figure. These happen when both sides are willing to bargain.
Your question is not very clear so no one can really answer it. What kind of settlement are you talking about? Is this some kind of judgement or did you win a lawsuit? Is this some kind of a malpractice and are you liable for this bill? You have to resubmit with all information
Sometimes the settlement is half. Sometimes it's a bit more than half. Rarely they will settle for a little less than half. Basically they have the upper hand.