Tiling floor cost

I'm moving house in the next few weeks and I'm going to have the kitchen and dining room tiled. The rooms are in an "L" shape and cover an area of 19 square meters. Currently there are wooden floorboards down which may be okay to tile on top of or may need prep with regards to putting suitable boarding down onto which the tiles can be laid so basically I'm looking for two quotes. 1. without preparation and tiling on top of the current wooden boards and 2. with preparation and the supply of suitable boarding on which to lay the tiles. I'll be supplying the tiles however I need to get an idea of price for tile fitting before I purchase the tiles (which will be standard porcelain or ceramic). Thanks Mat