i agree with you on the fact that they are over priced and a normal decent condition 575 coupe can be be had for half the value. The SA commands serious money as only 559 were made and 57 in rhd u.k form. They were around 200k new.
Read an interesting feature on the 550 barchetta in classic and sports car couple of months ago, the guy who was testing it reckoned that in 2 years they will be touching 200k. I find that very hard to believe, o.k only 448 were made and only 42 uk rhd but i can not see them appreciating around 70k in 2 years.