Memorabilia linked to World War Two German dictator Adolf Hitler and his Third Reich is perhaps the most controversial on the market.
But Dmitry Lomakov, the Russian curator of Moscow Museum's stunning collection of second world war automobiles, has an altogether different view.
"Buying a Nazi car is like sticking one finger up to Hitler," he told UK newspaper the Guardian.
Earlier this week, Lomakov certainly did that when his collection acquired the ultimate trophy: a midnight blue Mercedes Benz 770k famously belonging to the Fuhrer himself.
The deal was brokered by Michael Fröhlich, a Düsseldorf car dealer, for an unrevealed amount.
Fröhlich says he found the car locked in a collector's garage, and verified it using the historic vehicles original documents and old photos.
The automobile itself makes regular appearances in Hitler newsreels.
After the war, it was reportedly sold in Austria, then shipped to a car museum in Las Vegas, before returning to Germany.
According to the German news agency, DPA, the armour-plated car weighs five tonnes, with 18mm-gauge steel bodywork and 4cm thick windows.
Because of the sensitivity and sometimes illegality of buying and selling Nazi memorabilia, both parties "double-checked" with the courts before brokering the deal.
Press reports claimed Hitler's car itself was worth between €4-10m ($6-15m).
Elsewhere, a tapestry hung in the Reichstag during World War Two and later captured by the Allies.