Kenwood KT-990D

I'm very (very) new to the hifi world and I've collected a few vintage and older items in the past few months. One of which is a Mint Kenwood KT-990D. Is this worth keeping or selling? What's the going price for this unit?

I really have no real need for a tuner, since I have on built in to our current head unit. How would I benefit from this model if I decide not to sale it?

Thanks guy, and I look forward to learning from this experienced, and knowledgeable community.