4runner, shaking on highway problem help

[ZagsElite]

i went and looked at a 99 4Runner Limited a guy was listing for $9,200 83K with a salvage title he said was given before he bought it in 2000 which checks out with carfax and says it was just body damage which i can tell some of the lower body has been repainted, not too noticible just some paint chips and scrapes here and there. the car is decked out, leather, 3 tvs/dvd etc and the guy seems to be loaded (just bought a 05 Tacoma) so he my be just trying to get rid of it but im skeptical of course.

so i looked under the hood, engine ran smooth no problems looked pretty new, it drove well until i got on the highway above 60mph the entire car started shaking a bit, not the engine or just the steering weel but the whole body seemed to be clanking and felt like it wasnt attached right. I could hear the clunking in the back and it was anything but a smooth ride, it got pretty violent at a point where you couldnt possibly mistaken it for bad road or something. I guess he tried to shake it off and pitch to me that it was cause he had the car lowered and the springs had to be cut is what caused it and I could replace the springs for about 300+labor. i told him theres no way im paying anything without this problem being fixed (or confirming its fixable) and eventually convinced him to meet me at a dealership tommorow to have it checked out, at my expense.

so my question is, is this even worth checking out? im not gonna lie and say I know a thing about cars, but is it possible this is just a result of the aligment, tire balance, springs, bent frame etc (ie something that will cost under a grand to fix), or is this for sure something serious and the car is about to fall apart. really what I wonder is if its really jacked, up why would he agree to let me take it to a dealer, and why would he have driven it for 5 years (since the accident) and spent so much money decking it out?

any input will be appreciated

[drdisque]

chances are that its a tire out of balance or a damaged rim, but it could be something more serious, especially if its coming from the back. This guy seems like a tool though, I wouldn't buy a car from him. The car also sounds very abused in addition to the salvage title.