planning our trip

We are thinking about coming out for a group hike this summer. We have budgeted airfare and food expense, but have not yet received our Travel Insurance Quote. We are not sure if this is a necessary expense, but want to make sure we have all our bases covered. For all of you guys who have coordinated group trips, what do you think? Is this something that we need to do or not. Some in our group have insurance, but not all. Any tips or advice that you guys have would be great. Thanks for helping us out.