So yes anything from 200-300 depending on wether you want the a proper job or not. I would always replace the ashtray and cover along with the dash conversion and this may increase the price depending on the type of trim you have, black plastic being the cheapest and carbon being the most expensive.
You would also require a cable set for the installation, so again this would be included in the above cost. It takes about an hour or more to do, so all in all the prices accurately reflect the quality of the work.