This is in AUS dollars but might help, that car has very high mileage for it's age:
E39 M01 Sport Sedan 4dr Auto 5sp 3.0i
Prices based on km 50,000 - 90,000 (that car has averaged 32680 km per year......or 2725 km per month...damn that's high!!)
Trade in price guide* $37,600 - $41,200
National average price - private sale* $43,200 - $49,500
Price when new (RRP) $100,775
all prices quoted are GST inclusive