I would say it all depends on your budget for streaming, most of the time its going to cost you money. I know when I have the time free I do streams for expenses, simple nice clear single camera set up that is easy to set up and break down, ability to run commericals/ads. Other guys have more money invested in equipment with multiple cameras and lighting so you will be paying them to come stream it plus expenses/baggage fees, this cost will end up to be several thousand I am guessing unless there are sponsors involved. I think if you are going to spend more than $3,000 on having someone stream your event then you might just buy your own stuff if you will be doing more events.
The big thing about having a streamer do it is they know what they are doing from all the hours of streaming pool plus they will promote your event which is helpful but takes many hours of time doing so which people do not realize. Personally I am not available to stream for the next 7 months or so but there are some guys doing quality stuff but figure out the expenses and add around a grand on top of those for a 2-3 day event and you should have your number, streamers gotta eat too, haha. For what its worth I think Inside Pool does the best free streaming I have seen but I heard are not cheap, Daniel with POV is probably the most affordable though and is dedicated.