I think the value of the Sky in coming years will depend on what is available as an alternative.
Hard core collectors will get their Sky cheap now, and I assume that is a small pool of buyers compared to the overall Sky population.
Investors (anyone hoping to hold the car and sell for a profit) have lower risk alternatives for their investment dollar.
The remaining buyers, people looking for a used, weekend sports car, will look at the choices available. If car makers stop making sports cars, we win. If other excellent sports cars appear at a reasonable price, we lose.
When I was in college in the early 70's, you could buy a Triumph or MG for very little. The car everyone wanted (if you couldn't afford a Vette or Porsche) was the 240Z. At that time, a lot of car for the money. The unreliable British cars were driven by a small group of hard core enthusiasts - but the general public went for the Z.