Best low budget speaker cable? HELP

My aunt just bought an inexpensive but fair sounding Onkyo TX-8211 reciever which is driving a pair of Boston Acoustic speakers. She needs to buy some speaker cable to replace the 22 guage wire that she has now. Her main stores in the area for inexpensive wire are Radio Shack, Good Guys, Circuit City, Etc.. but she is willing to order on line.

She would like to keep the cost under $50.00 and needs about 40 feet of wire total.

Thanks for any input on this low fi question :)

Montana Rane