Now you can buy - like March 2012 - Sigma SD15 + 18-50/2.8-4.5 for € 379 incl. 19% taxes.
---> Sigma SD15
I bought my Sigma SD14 + Sigma 18-200 OS some years ago for a little bit more than 400 €.
Differences SD14 - SD15 are minimal (bigger display 2.5"-3.0", SDcard instead CF, 3200 ISO max instead 1600 ISO)
Both have no video, buuuut same FOVEON sensor with > 14 Mpixels. SD1 has 46 Mpixels.
I am using with SD14 a CF adapter for SDHC cards.
Some pictures from today