Produced in limited quantities from 1973 to 1977, the Porsche 911 2.7 RS Carrera is considered by many Porsche purists to be the ultimate 911. This is especially true of the Sport Lightweight variants, of which only 200 were made. According to research done by the Discovery Channel, the average price paid for a 2.7 RS has gone up by 669 percent over the last 10 years. Nothing else even comes close to these frankly staggering figures.

Classic car prices have, of course, generally gone up across the board over the past decade, and the RS wasn't exactly cheap 10 years ago. But this sudden boom is something else altogether, and nobody seems able to explain it. In 2004, you could get an RS for an average price of about $101,000. The average price today has climbed to $777,000. The price of a Sport Lightweight is going to be even more, but Discovery didn't break the figures down into different variants. But a good indicator is the one you see in these pictures, which will be auctioned in February and is expected to go for upwards of $1.4 million.