Why is the Lotus Esprit such an expensive car?

The Lotus Esprit has a fairly good choice of engine blocks making the engine itself very expensive. On top of the engine being expensive the Esprit has become a collectors car and being such has been almost impossible to get one. Collectors or just regular users know the rarity of this car being on the market and know that many people will pay a lot for one thus they sell them for prices that seem a bit excessive.