[wtwo3]

It's more or less a math exercise to determine the best option. Look at the buy out price, and compare it trade in value at the dealership (hint: the dealer would be foolish to give you a trade-in value higher than your buy out price, so don't count on that.

The other option is to look at what value 3rd party companies like carvana/carmax/zoom etc would place on your car, and determine if that's higher than your buy out price. (Probably not because of BMW's inflated residuals)

A 3rd option is to scour the used car scene and see what private party resale value is for your car and compare that to your buy out price. (Again, highly unlikely that you'll come out ahead).

There's rare exceptions where it would make financial sense to buy out your lease, and with most of those exceptions it would have made more sense to just buy the car to begin with instead of leasing.