This may be decided by the location you choose: some pubs have an employee or company who is the "quiz co-ordinator" or similar, and say that if you want to have a quiz in that pub, then you must use their organisation, and pay their fee. Pubs mainly do this if they have experienced badly organised table-quizes, an are worried about getting a bad reputation..
But if you can choose whether to use a quiz-company or not, there are some things you should consider.
Cost vs volunteer time and commitment
If you have volunteers doing all then work, then you will not have to pay any kind of management or administration fee.But you will need help from a lot of people in order to run a successful event. If your volunteers haven't been involved with a table quiz or similar event before, then they may need training in how to do their roles.
And it means that the volunteers cannot be involved in the event in the same way as the other participants - this can be a problem if your goal for the event is about team-building rather than fund-raising.
Quality of organisation
Companies that run quizzes on a regular basis have the process down to a fine art: they can generally manage the event with only two people, and they know exactly what needs to be done, when and how to do it.That's not to say that volunteer-run quizzes are never well organized - bit it does take a lot more effort from the organisers to make this happen.
