I set up my office network/AC for less than $5000. Like Nephron said, I spent hours drilling holes in the walls, pulling wires, setting up network, installing software, etc. I only hired a guy to crawl and pull wires through the attict. So far my P2P network works fine. The only mistake I did, I got refurbished computers made from used parts instead of new ones. They were very cheap, but didn't last too long, and some of them were slow because of limited RAM, so I had to replace them later.
