In my books you can afford it, life is too short - go for it.
I'd put some money down (~10K) on new one to keep payments reasonable - you dont spend a lot up front, you keep your monthly savings still in similar ballpark. It really depends on how personal view on parting with lots of savings .
Hers : 2015 328xi MSport Silver/Red
His : 2016 X3 35i MSport Silver/Mocha