My client is an Architect, and is considering getting a second/new IMac, should they come out with a 4 core, which has been mentioned out there

My question, is how would a Network benefit him? He said he's interested in Networking the two computers, but i'm not sure if he will need to get a second copy of the Architecture software, and in general, i'm not sure how it would benefit him?

I know he should be able to access the same Printer with both units, and the external hard drive from both computers (should he go with Airport Extreme, I believe it's called)

But how does this serve to help him? What are the potential benefits/uses of a network?

Also, are Wireless Networks pretty easy to set up, and is Airport Extreme a good choice for Base Stations?

Any, and all info is appreciated