Legal fees vary according to the complexity of your particular situation. They vary according to the hourly rate and basic fee charged by the law firm which you choose and by the total amount of time your attorney must spend to adequately represent you and resolve your problems.
A simple, uncontested case warranting a minimum fee might be one involving a couple without children, without real estate or significant assets and both parties working and earning a living. In contested divorces whether the dispute involves the grounds for divorce, custody, alimony or property settlements, your attorney will need to spend more of his time in resolving such issues which will obviously be reflected the fee he charges you.
The cost of your divorce or dissolution can vary widely. After your initial consultation, ask your lawyer to confirm your fee arrangement in writing and ask what problems or issues might complicate the divorce and make it more expensive to you.