Do you want a semi classic sports car that is relatively easy/cheap to maintain and holds it value?
The Porsche 911... Specifically the 3.2 Carrera with G50 gearbox.
And yes a good one is expensive to buy but you'll never regret spending the money up front ~ I know I'm stating the obvious.
My 78 SC has given me almost new car reliability in nearly 12 years of ownership.
The biggest problem was the gearbox and I replaced that with one from an 83.
Other than that it's been oil/filter changes and brake fluid renew. Normal parts like brake pads and stuff goes without saying.
Zero rust... Starter motor ~ original. Alternator replaced 6 years ago.
In other words better than some so called new cars from the dealership.
OK. So you want a semi classic non Porsche sports car that is easy/cheap to maintain and holds it's value.
I really can't think of one that does what the Porsche does.
It's just the way it is. New Ferrari, Maserati, Forget it... Budget 5 to 6k a year just to have it in your driveway. That doesn't include insurance/registration or fuel.
Lamborghini??? Much the same. Have you seen a 30ish year old Lambo next to a same year Porsche?