For my daughter’s wedding, we ( and the in-laws )made a budget and stuck to it. Her gown was rented ( for $400 ) from a woman who rented gowns as a business to support her husband in kolel. My daughter didn’t see the need to have her parents spend thousands on a dress she would only wear once.
I haven’t said this in a long time but I agree with Joseph. A true Ben Torah would tell the in-laws to use that $2000 towards supporting him in kolel.