Not exactly Apples to Apples but I sold my garage kept 2000S with 134K miles in July for $7,200. Not perfect but 10 years of maintenance records, top with glass window and good tires and brakes. No leaks and everything worked.
On the other hand, as the cars slowly get retired or scrapped out, the remaining inventory is bound to increase in value. Even at 12 k a boxster is a tremendous value anyone price a new one lately.