Price on white gold prong setting vs platinum prong.....

[Charmed]

My husband and I are purchasing a new diamond ring. We are in the process of picking out the best princess cut we can find. i have selected a classic tiffany solitaire setting in yellow gold. What would be the price difference if we choose to go with platinum prongs instead of white gold prongs? What are some of the benefits? Does it really matter? If we are doing this a second time, we want to do it right.

Thanks in advance.