Pricing is all over the place. One highly regarded Porsche restorer/dealer told me that he thinks that Speedsters "done right" are in the $150-200k range. Yet I know of a BEAUTIFUL Speedster that just went for $112k; Bali blue (wrong color but stunning) flat nardi and five Rudge wheels which are worth $15k by themselves. This was truly a top of the world car that went for short money by current market standards.
Take a look at some dealer's inventories and prices.
http://www.paulrussell.com/
http://www.autosportdesigns.com/
http://www.astonmartin-lotus.com/home.php
Speedsters ain't goin' down, nor are most other classic car prices decreasing.
Regards,
Steve Ross