I was under a similar conundrum, wanted to buy a 7 series as a toy, since I didn't need it. Came across a beautifully kept 750i, that was run 93k kms(~58k miles) selling for 39k CAD(29k USD). It may be worth mentioning that it didn't come with an executive package, or the long wheelbase.
However, I purchased it 10 days and has been an absolute pleasure to drive. The 4.4L V8(as notorious as it may be) has been a pleasure to drive, and the raw power just puts a grin on my face end to end whenever I take it for a spin on an open road
Adding a few pictures of the same!