Today there are so many choices and techniques when it 
comes to the purchase and installation of tile. Will it be ceramic or porcelain?. Will there be any custom elements like seating of recessed niches? Will there be unique patterns or intricate designs? The answers to these questions and more will be needed to quote the project. An onsite quote without these answers should be highly questioned!
A bit about substrates. A substrate is the surface behind the tile. If it is used in a wet area it needs to be completely impervious to water to be building code compliant. There are many different products available to accomplish this such as cement board, adherable fabrics, and even a paint on solution. Corrosion proof fasteners should be used when necessary.