Richie, they retail at £9922 including UK VAT from Barrus the UK supplier.
http://www.barrus.co.uk/products.php?sectionid=52
You could also give Barnet Marine (
www.ribs.co.uk) a ring and ask them how much they can do one for. According to the Dave at Marine Motors Cork, Barnet can sell them at a cheaper price than Marine Motors buy them at!! Definitely true for my 150 Optimax anyway.
Is it going in an Excalibur??