Two other perspectives to consider:
My law professor from my MBA program put it this way: "lawyers are paid for what they know, not what they do." In other words, the value you get is not only from the assurance that it's done "right," but also that it should take less time than you doing it--not just writing it, but researching, filing with the state if needed, and backup support if and when it does come into force. It's the avoidance of your time and hassle more than their sweat equity.
Another perspective: estate law, like insurance, is something many people avoid. It's a hard sell; people either aren't interested, have other priorities, or find it distasteful. So, practicing in this area requires a lot of marketing time and expense. The cost, then, for those who do get it has to incorporate all this non-revenue time. You are paying for all the people who they meet with, and then say no.
I am not an attorney. (or even an insurance salesman) The costs drive me nuts, too, but you can only control your own reaction. I provide these perspectives in the hope that you think of these services as businesses, not just a trade you are hiring hourly. This said, you certainly have the right to direct / minimize the work you are asking of them; just understand that they typically deal with people who have no idea what the process is--it may take some time for them to figure out that yours is an informed decision.