I did a couple inquiries on new 2007 S2000's. I got numbers back between $12k-$15k plus my trade. I was hoping for $9k-$10k but I guess I'm dreaming.
I read on these boards that some dealers are selling new 2007's in the $28k. Where are these dealers?

 

I think the $28K you see posted is rare or after a bit of negotiation with a dealer that has 4 or more new S2000s on the lot and few interested buyers.
I certainly think being willing to walk away from the dealership helps. I wasn't and they knew it, so I bought my new 06 last summer for just under 31K. But I haven't looked back since, and I'm very happy with my decision. So go to the 12K dealer, and try to talk them down another 2K and see what happens.