Hi ya Jason. I am going to start of with a yarn about a grand uncle who was a self employed sales rep, and bought new cars every 2-3 years, his rationale was that he couldn't afford to spend the time on sudden repairs, beyond the standard servicing schedule. so the second it needed anything major ( water pump/radiator/ belts) he sold them.
My gut feel is to move the car on while it still has some value to it, especially since time is of the essence here.
The only issue is if you were to get an 6 or so year old F3*, you will be coming up to similar issues with the wear and tear items, except you will be driving a car that is "worth" spending the money on. https://www.trademe.co.nz/a/motors/cars/bmw/320i/new-listing/3075362349?bof=wbGF0k7Z