I'm pretty sure the new fixed price is the no-show fee ($188 main dining, $250 chef's counter), so it will be that plus whatever drinks you order, tax and tip.
Whether something is worth it is completely subjective. We had an amazing time at the chef's counter, but that was just for 2 people. I was glad we went because the newly remodeled restaurant is gorgeous, but for us it's definitely a celebrating something special reservation (in this case, we were celebrating that they reopened - lol) not a place to eat every time we go to the parks.
You know your family best. If they enjoy fine dining, and the cost isn't prohibitive, I would keep it.