I have no idea how much these cost.
We went to one recently at the Briscoe Western Art Museum. I thought it was nice. We had a good time.
http://www.briscoemuseum.org/event-rentals/weddingsA wedding at the Majestic Theater was pretty amazing, but probably way out of your price range.
The most fun I had at a wedding downtown was on the veranda at Mexican Manhattan. I would bet that it wasn't that expensive. They rented a river boat that kept making circles and takings guests on tours. That was fun after a lot of free margaritas.
Didn't enjoy the one I went to at the Weston Centre.