collector: DeLorean or other odd-ball types. DeLorean was only in production for two years.
real sports car: used Cobra kit car. Should be able to get a nice one for close to $45K. Older corvette, maybe get an anniversary edition for more collector value.
One is'nt a real sports car, the other will never be a collector. The corvette could be collectable if it's all stock. For both in one vehicle I'd agree with an older Porshe or Ferrari in that price range.