Always ask about all fees up front. Some services are not clear about what hidden or extra fees may be attached to a particular service. Ask if you are upgrading or changing the basic package to ensure you are not dealing with a hefty fee increase.
If the wedding package includes photography, decorations and videography be sure to ask to see samples of the completed projects. Also, if you have specific colors or decorations you want used make sure you ask about what the company offers and what they could recommend within your price range.