welcome, Graeme. Would be helpful to know which part of the country you're in - please update your profile.
How many kms on the 545i? If you're new to the 545i, important to check and verify state of the valve stem seals (common failure on this model), and whether there are coolant leaks (the coolant tube that runs front to back in the Y of the block). Both of these items are expensive if you're paying for the work to be done.
A well-sorted 545i is a joy to drive. 333hp and 50:50 weight distribution and 1650kgs, they're a great tourer, yet surprisingly nimble with Dynamic Drive suspension and Active steering. If you're interested in the long-term experience and different repairs and maintenance I've done, take a look here: