I don't quite understand the poll options and how they relate to my situation, so I'll just write out what happened.
I had already negotiated on the cost of the new car, so I'd picked a dealer to buy my new car from, without mentioning that I had a trade in. Then I went to CarMax, and they offered me $4k for my car. After that, I went to the dealer I'd already picked, and they too initially offered me $4k. I sat there and said "I have an offer from CarMax, and I was hoping for higher than what you just offered on the trade in so I might just go back to CarMax to sell them my car" without saying that my CarMax offer was for the same damn amount. The dealer came back to me, offered me $5k for the trade in and I took it. I will say that this particular dealer advertised themselves as a bit of a specialist for the car I have/had (Prius - I was trading an older model for a newer model), so they were quite keen to get the trade in. I think it would not have necessarily gone so well if I'd had a random other car to trade in.
So I guess CarMax was on the low end of the range for my trade in, but it's not like I really heavily negotiated or got an actual range or sought out different trade in options. I don't remember what the KBB value was at the time, but then again I'm always confused about how you tell if your car is good or very good or whatever condition. Plus, in my state if you trade in and buy a new car in the same transaction, you only pay sales tax on the difference in price, not on the full purchase price of the car, so that swayed my decision quite substantially.