It's not that many miles for a diesel, the engines are quite good on these and quiet(ish) compared with some other diesel engines, the only thing that went on my engine was the EGR valve, which was sorted at about 26K and had no further problems after that.
My Mjet 1.9 had about 79.6K on the clock before trading it in.
The biggest problem with these is the gearbox, in that it uses the dreaded M32 gearbox, which i would be more worried about than the engine to be honest, they're like paper mache.
My gearbox was starting to wine in 5th / 6th and it was starting to judder in reverse and first
For a reconditioned gearbox with fitting + replacing the clutch whilst the box is out you are looking in excess of about £1500 but that's from a gearbox specialist company, but you can pick up recon box's on ebay for about £750 but they normally ask for your old gearbox in exchange.
Some Vauxhall's also use this box too, the astra 1.9 in particular, and my mates car was no exception, he had to have his replaced.
Apart from that they are quite good cars, i owned mine for just over 4 years without too many problems, never off the road and used almost every day, picked it up with 6K on the clock.
Out of interest how much is the car advertised for?
Neil