One of the first Aluminum Rockhoppers to come with front suspension.
Tell him to fix it himself. The money spent on materials and tools is much cheaper than what most shops charge for labor, and in the end you have a greater knowledge about your bike. Refer him to these sites if he has trouble.
It depends on exactly what will be done to the bike when calling it a "tune up." That's very non descript language. Either way, as has been mentioned, anything done during a "tune up" can be done at home, and typically without a lot of specialized tools (save maybe for a chain breaker).
The only thing much different between mountain bike maintenance and road bike maintenance is suspension and brakes.