Curious about what a Miura cost years back? These prices include information from everything I've obtained from market reports and old ads between 1976 and 1990. All cars listed are decent original examples (I excluded the basket cases). You can tell that most owners made sure their Miura was concours before selling during the crazy price boom of the late 80's.

September 1976: 1967 Miura p400 with 9800km- $11,500 (Hemmings)
October 1978: 1969 Miura p400 with 12000mi- $18,000 (Cars and Parts)
March 1980: 1972 Miura SV with 5600km- $49,500 (Market Letter)
November 1980: 1969 Miura p400 with 19000km- $28,750 (Hemmings)
May 1982: 1970 Miura S with 33000km- $35,000 (Old Ad, Misc.)
September 1985: 1969 Miura S with 28000mi- $45,000 (Deals on Wheels)
August 1987: 1967 Miura P400 with 30000km- $40,000 (Hemmings)
January 1988: 1970 Miura S with 26000mi- $64,500 (Hemmings)
January 1988: Miura S Spyder- $150,000 (Hemmings)
May 1988: 1972 Miura SV with 27000km- $125,000 (Hemmings)
May 1988: 1972 Miura SV (100 point car) with "under 2,000 original miles"- $175,000 (Hemmings)
July 1988: 1969 Miura S, Restored to "as new" specs at Lamborghini plant, original euro car, 59000km on chassis- $100,000 (Hemmings)
July 1988: 1968 Miura p400 with 85000km- $52,000 firm (declared to be "the last original at this price!" and "high mileage but as new" by the seller). (Deals on Wheels)
September 1988- 1973 Miura SV- Low Miles, $210,000 (Hemmings)
May 1989- 1972 Miura SV- $275,000 (Hemmings)
October 1990- 1969 Miura S- $295,000 (Hemmings)
October 1990- 1991 Lamborghini Diablo- $500,000 (Hemmings) (Just for Fun!)
December 1990- 1967 Miura P400- $198,000 (Hemmings)
December 1990- 1971 Miura SV- $475,000 (Hemmings)

If you recall, prices began to decrease again in late 91 at a slow rate. The market decrease accelerated around 95, and the most recent rock bottom for the Miura was 1998-99. They began to increase again in 2002, and skyrocket in 2005 to the Half-million dollar cars of today, and still climbing!