Wedding planners

Usually the weddinf coordinator at the venue just deals with venue things such as making the day go smoothly from their part (venue) I would clarify if she deals with your vendors, such as directing them, answering their questions, paying them ect. That's what a planner that you hired would do day of. I would say #1 evaluate your needs for the day considering what you want and #2 clarify the role with your venue.

Personally I wouldn't it would the an extra cost. However, if you and the venue's planner don't click and you feel you need one then I would.

I would say it depends what the planner is for.

The planner who is helping me with my wedding has been great, however she won't be there for the day-of and is only helping with the planning process, and they aren't responsible for any of the vendors we've hired.

If you want someone to be there during the day-of (or if yours does that), make sure to see what they are responsible for (is it the whole wedding and other vendors or just the venue operations).

That should be able to help you make an informed decision if you need to spend the extra money on a co-ordinator.

It depends on the size of your wedding and what you’ll need assistance with, especially for “day of”.

Do you want someone to plan your entire wedding?
A day-of coordinator?

I’ve noticed that a lot venues have event coordinators who oversee things for day-of but not all aspects of wedding planning.