I normally do my own work but if you get a mechanic to do it for you be sure he/she does some preventive maintenance. As in replacing the timing belt while the car is torn down. Some people even replace the water pump while you have it apart as well. To give you something to base it from when I did the Head on the Breeze it cost me just over 300 dollars in parts alone. Again that is with replacing all the belts and what-nots.
The thing to watch out for is oil leaks. If the car got hot enough it could have burnt the rear main seal and you will have a huge oil leak. Which is another job in its self.
Good luck and dont get screwed. Request to inspect the vehicle just before they put it back together to make sure they put in a new water pump and timing belt (recommended). I am paranoid when it comes to mechanics, for some reason they all seem to be crooks.