If the 10-year out-the-door amortized costs were identical for NSX's and for Sky's, wouldn't half of us be driving NSX's?
Somebody go buy a 10 year old NSX, put 100000 miles on it, and tell me it is still worth what you paid for it and how much you spent for maintenance, insurance and upkeep.
If it sounds to good to be true, it probably is.
So to answer your question, if I was rich I would buy the 10 year old NSX for the driving experience. Since I am not rich, I would buy the Sky.