>Even expensive sports cars like the BMW M3 and Porsche 911 kept up with inflation. A 2003 E46 M3 cost $46,545 ($78,729 today), while a new M4 (the two-door version of the M3) is only $74,300. In those 20 years, power went up from 333 to 473 hp. Even the 911 Carrera, which seems expensive at $106,100, is way cheaper than the 996 model at $72,435 ($122,521 today).