You can get an estate plan online for a relatively cheap price. However, that estate plan might include far less than what you really need. This can lead to problems for your estate after you pass away. Those problems will be far more expensive to fix, than hiring an attorney now to get the appropriate plan for your estate.
How much you will have to pay an estate planning attorney, generally depends on the complexity of your situation, as well as the attorney's experience and local market conditions. If you have a complex estate with many assets, you will most likely pay more for an estate plan.
It is smart to consider pricing when it comes to services, but it is most likely a good idea to retain an estate planning attorney to advise you on creating an estate plan that fits your unique circumstances.
Reference: CNBC (April 26, 2018) "How to protect your family beyond death — without losing your shirt."