Ages ago, I read a science fiction short story in an anthology of Eastern European, Cold War-era science fiction. It involved a man leading an ordinary life who finds a lovely sports car at an out of the way gas station and finding-out it is being sold at a very modest price, and then buys it.

His life changes instantly and the next thing he knows he is meeting beautiful women, dashing world-travelling men and getting invited to fabulous parties and the like. He's sure the car is at the center of the change. Then he notices a small sore on one of his feet is not healing, and as the weeks go by the sore gets worse. He feels weaker, anemic. The car is drinking his blood. The rewards were great, but the price was too much. The car would kill him, so he winds up offering it for sale at a modest price.