Dandy Don explained it well except what you would consider reasonable compensation and what most attorneys would call reasonable compensation are MILES apart. Most will charge the maximum the law(written by attorneys,for attorneys)will allow, even if it is a "clean" estate. Then they will tell you that the law dictates what they can charge and you are stuck. It is no different than when you go to buy a new or used car. The car salesman will charge the top price if you are willing to pay and they will smile all the way to their bank.
The reasonable compensation of 6% can be totally outrageous for a simple estate. I have been involved in many that can easily take less than 8 hrs. and the last one I was involved in took less than 20 minutes for a $200,000.00 all cash assets.
Choose an attorney carefully, and discuss fees up front or there is a good chance you will get "cleaned".