https://www.e90post.com/forums/showthread.php?t=1517476
this goes into great detail but is US based.
The N52 is very reliable as long as it's been maintained. Few guys on this forum have got them to 300-400k miles.
Electric water pump seems a common failure and due to access labour costs can be high. OFHG common failure too just like most BMWs of that era.
Worth checking struts or seeing if they have been replaced as even low mileage break due to age and terrible UK roads. Battery is a grey area as at that age they can get bad but i have a 11 year old original still putting out perfect values.
Realistically if it's been serviced and hasn't been crashed or something then it should be solid.