Did you know that airlines, hotels, and other tourism providers can offer the organizer or host of a group complimentary travel or discounts on your trip? Depending on the size, you can definitely save by booking a group trip.
Turkey is a busy place and has so many different cultural attractions, it can be hard to choose what to include on a group itinerary. Be sure to avoid a "one size fits all" approach, because some people will want to try out a Turkish bath and some won't. Others will want to spend an hour or two in the bazaar, and others will want to spend all day. You want everyone to go home feeling like they had a good holiday, and a schedule that gives everyone some flexibility so that part of the time you're enjoying structured, scheduled group appointments and that part of the time, everyone's allowed some serendipity to go and find the things they'll enjoy the most.