I think you should absolutely buy it - and if 6-12 months from now you decide to sell it you certainly would have that option (and make some money)
I personally wouldn't get any extended maintenance or warranty but if you do opt for a warranty forum member @GOLFFRR sells oem bmw warranties at really steep discounts and can sell them across state lines
Here's a link to the warranty pricing thread
https://f80.bimmerpost.com/forums/sh....php?t=1676787