Nikon charged me $75.04 on 1-14-08 to replace both clips including return shipping. Others have said that the replacement clips were grey and probably a stronger material. The clips they put in mine look almost identical, perhaps a wee bit darker.
I'm thinking the secret to longevity is removing the batteries when not in use. My clip broke when I was not using it. Evidently constant pressure on the clip fatigues it.
Scott Chapin Powder Springs, GA, USA Nikonians Team Member