It is a Montblanc Solitaire 144 Ramses. The nib consists of 18-carat gold (750 stamp); the silvery-looking areas inside are not a platinum inlay in the literal sense but a platinum or rhodium intarsia, which visually creates the bicolour effect. A flat-rate value statement for used writing instruments is not possible, since the price depends decisively on condition and market demand; eBay comparison sales are the usual orientation.