Well, I have seen around the same vintage Sunfire's go for ~$250-300 on Craigslist. With the consideration that Sunfire is still in business and B&K is not.
I would guess $200. It's a 10 year old receiver.
If you are asking this because someone, somewhere, has one for sale and already thrown a price out there, I would hope they haven't asked something ridiculous like $600-700.
