If that playfield is in as good a shape as it appears from the pics (impossible to tell without HD pics), then Id say this is close to a steal. This is coming from the guy who has the other TZ for sale here for quite a bit more. But, I have to say, Im so on the fence about selling it cause it is just such a great pin. For quite some time I wanted to sell it to pick up an AC/DC or Medieval Madness. ....and, for me, Ive played ACDC enough to realize I like TZ more and I flat-out bought MMr and even though Im playing more of the MMr cause its still new Im thinking TZ will have more staying power.
I wouldnt drop it a penny more. Get some HD pics of the playfield with glass off and put it on Kijiji. Its a timing thing, not price. For 6,8k TZ blows away all the new pins you have to pay 10k+ for. Just wait, a buyer will appear...