What's It Going to Cost?
Although you can buy a DSL or cable modem that is integrated with a Wi-Fi router as a single unit, this is not that common and has a couple of drawbacksnamely a probable higher cost and less ease of upgrading the modem.
It's really dangerous mentioning dollars-and-cents figures in a book for several reasons. The cost of computer-related devices is constantly changing, mostly going down over time as specific technologies become more mainstream. By the time you read this book, it's a safe bet that it will cost less to create a Wi-Fi network than it cost as I was writing the book. (And it was inexpensive enough then.)
It is also true that there are many different possible network configurations, as explained earlier in this chapter. Your network is unlikely to be my network. The cost of setting up your Wi-Fi network will largely depend on how many devices you need to equip with Wi-Fi.
All that said, the short answer is that it won't cost you much. It's truly inexpensive to set up a small wireless network capable of serving a home or small office. (Commercial grade equipment that can handle many multiple users is a different story.)
As of right now, you can buy an excellent wired router and 802.11g Wi-Fi access point for about $50. In addition, you'll need your laptop or laptops that use Intel Centrino mobile technology. If you don't already have an Internet connection, you'll need to pay for a connection, and buy (or lease) a cable or DSL modem. Finally, expect to pay about $30 each for cards used to add Wi-Fi to older desktop and laptop computers.