These things go on sale all the time. Either check Amazon for "deal of the day", or if there's a MicroCenter or Meijer or Fry's in your area, check if they have sales every so often.
I really like the WRT54G series because I can use the Tomato firmware (which I like better than the Linksys firmware), but it's a bit long in the tooth now, especially since Wireless N has been out for a while. My router has been chugging along for years, and is still doing good, although I've had the wireless turned off for like three years.