Used car buying advice?

I'm looking for a car to replace my old one that got totaled, and I can only spend $2000-3000. I saw one I wanted at a dealership. Its a 98 Lumina with 90k miles. I checked out the blue book value, which is only $2480 max for retail value. But the dealership is asking $5999! How can they think someone would pay that much? And what should I say to them to start negotiations?