To bi-wire or not to bi-wire?

I have a pair of B&W 804 Nautilus speakers. They are currently bi-wired with Kimber 8TC cables. I am going to upgrade the cables and was curious as to whether there is a significant difference in sound with bi-wiring. Most of the cables for sale on Audiogon are not bi-wired. If I stay with the bi-wired cables it narrows the field for some good used cables.