If all checks out then it should be fine and a lot of car for the money although purchase price is only one aspect of car purchasing
The possible "pitfalls" I can think of are:
1. Tax effectively makes it £10.5k.
2. Tyres check the inside front edges even if they appear good.
3. Discs last approx 40k miles from what iv seen so they will either be done or pretty worn I'm guessing. Checking is easy as on the M a large lip develops on edge of the outer face of the disc usually.
4. Servicing - Ins II may be lurking assuming it's not already done
If you purchased this car and ended up buying tax, a pair of tyres, discs/pads and the next Service is an Ins II it could work out cheaper to buy a "better one". I'm reckon a 100k mile M would be difficult to shift too although I may be wrong and depends how long you keep it, price, condition, etc. I also reckon some nice cream seats or black ones would make it easier to sell too.
Just for example i'm on the other end of the scale I purchased a low miles AUC car for £15k and in 17 months of ownership all I have spent is my tax renewal (£500) as it came with a year.