Actually, if you follow the pricing trend of MB cars over the years you'll find a couple of interesting trends. Prices started coming down when more luxury cars were entering the market - most notably the Lexus - providing competitive pressure. Also, back in 95 I believe the US Dollar was rather weak against the German Mark, requiring more dollars to buy German cars. It would be interesting to dig up the prices in German Marks for those examples you gave.
95 E320 Cabriolet, 131K