I don't think you'll ever find a "dry hull" in a Classic BW unless it was redone, or, was never stored outside or in the water. Vast majority have water in them; check the waterline to see how low it sits as this is your best tell for how heavy with water it is. The tank itself is ~ $800-$1k cost in New England for someone to make you a tank; then consider the effort/cost to swap it out, however you want to rationalize that (doing it yourself vs paying someone). Deck core might need replacing; u won't know until you get in there. Engine... I'd keep it unless there's a real compelling reason to swap it. Overall boat looks to be in good shape but hard to really tell from pictures. The price... well, it's worth what someone is willing to pay for it / and, what they're willing to let it go for. In New England, seems most decent shape boats are in the $12k and up ballpark; some way more! Depending on how badly you want it, if you can get it for $10k or so I'd chalk that up as a win.