Morning Tony
Welcome to the Forum
As with any used car purchase "Eyes Wide Open" general condition and service history are paramount. 97k is not excessive, what engine transmission and accessories are fitted are all things that will effect the price you pay/negotiate.
Whether you can carry out repairs yourself or not again will effect whether it is worth the risk
One of my sons brought a very cheap 09 325d touring Auto with a cracked exhaust manifold and a clogged EGR plus a couple of other small related engine issues £600 and 3 days work and we had it back in fine fettle, 3 years on it is a really nice car to drive.
So it depends on you and your ability both my sons have grown up helping Dad tinker build and fix all sorts of stuff so are very capable home mechanics. Had they not been and had to rely on a garage the 3 series would have cost around £2k I would estimate at garage rates.
Good Luck
Dave