Maybe Boxster's are harder to come by up north but here in LA they are still a dime a dozen. More than 25 Boxsters listed on Craigslist for under $12K. The two examples below give a good idea of the current range of price vs mileage in LA. Of course, a newer model or an S will cost more but many people are just looking to get into the Porsche game and the price of entry is pretty darn low.
1997 Boxster, 110K miles, clean title, clean car - $6500.
Porsche BOXSTER $6500
1999 Boxster 44K miles for $12K!
1999 Porsche boxster, Clean title with 44,xxx miles!