Heh, I actually thought about bidding on those. (the flat disk kind, not the star that you like). I'd email the seller and see if he'll sell you the centers alone, since he seems to have a bunch of them, and was only charging $100 more for those caps.
Do you have any pics of your car with the 430 rims? Like I said, I've been thinking about replacing my 10 spoke alloys with the 18" chrome 430's Email me at synthesis77@yahoo.com if you've got some...