Here is it:
The new BMW M3 Convertible goes on sale in April 2008 and costs £54,655 OTR. The optional M DCT Gearbox will be priced at £2,590.
(M3 Coupé: £50,725 OTR and M3 Saloon: £49,310 OTR).
It is about £3930 more.
I think US price will be around 61K.