As sig says, iFixit is a good place to start.
A lower case will probably cost you about $240US used.
An upper case (the bit the keyboard sits in) will run out at about $300US used.
The screen assembly is usually sold as a single unit (maybe $700US used)
None of these prices include labor. They assume you do the job yourself.
As you can see, it is an expensive business to replace these parts if more than one is damaged, and it would probably simply be substantially cheaper to buy a complete equivalent second hand computer than to have the parts you mention professionally replaced.
Other potential US sources include
http://www.powerbookmedic.com and
http://www.powerbookguy.com.
New Apple parts will cost significantly more again.
If you DO have insurance, then it probably is worth using it, despite any excess . By the sound of things your boss has done way more than a couple of hundred dollars worth of damage to the unit. It is easy to do if you accidentally lean on them, even just once, when standing up.
The new unibody units are much, much tougher, by the way. If he has done that much damage in such a short space of time I reckon you deserve, and he needs, one of the new unibody models! Probably make more economic sense , too!
Cheers
Rod