Rust is the killer.
I got mine at 254k miles 13 years ago and it has somewhere around 375k on it now with the passenger seat falling out. The soundproofing inside and the undercoating outside sandwich the floor pan and if it is rusting only way to tell is poke hard.
First thing I'd do is jack the car up by the jack points. Hear any funky noises or see anything shifting you know there are issues.

__________________
95 E300D working out the kinks
77 300D, 227k, station car
83 300CD 370k, gone away
89 190E 2.6- 335k, no more
79 VW FI Bus- 145k miles, summer driver
59 VW Beetle ragtop- 175k miles
12 VW Jetta- 160k miles