I paid $11,350 last year. 82 Targa with 82k miles. Its a nice driver. I would say I have put in around $3500 since then, not all of which was critical stuff. Biggest chunk was $1800 for clutch+1st/2nd synros and some general tranny lovin...(get yer mind outa the gutter ya perv.)
Funny, I bought a boxster 5 weeks ago, and yet even with the sunny weather here, she has sat in the garage all week. Boxster is a great car, but my SC....she's like comfortable pair of blue jeans.
They are great cars.