I bought one years ago for $200 and it was in 99% condition. I have a friend who's uncle gave it to him still in the box, 20 years basically unfired. Less than a 25rd box of shells through it and he wound up selling it to me for $200 and it was really one of those "Hey man, I know you're not really in the market for this type of gun but I need cash so if you can swing it, I'll let it go for $200". I bought it even though I had very lil interest in shotguns at the time and I thought 870's were a dime a dozen and it sat in the corner for a couple years until I needed some currency toward a rifle I wanted and let it go for what I paid.....
I still kick myself to this day for that stupid mistake. It had an engraved reciever and beautiful wood, don't know wth I was thinking but I made it my mission to buy another, this time with a good trap gun in mind, I ended up paying considerably more. Live and learn. They are great guns and I keep an eye out for them now. If I find another for a decent price I will be all over it. I shoot trap with a '69 TB and I love it. Excellent made shotgun.
I had the opportunity to buy the twin TB to my 12ga in 20ga last year and it was in excellent, LNIB condition but I hedged against it because I don't have much use for a 20ga and it was $750........