17k mileage is nothing, for a car that will last for years. You can buy an extended BMW warranty and be set to 100k miles. You can also buy the extended maintenance package and also have that extended to 100k miles.

See if you can work in a warranty @ $40k. It's not a bad deal, in my opinion. X5s hold their value quite well.

These really are the best SUVs in their class. The blow the Mercedes products out of the water, in nearly every regard.

I say go for it, if you're not going to buy used. I see no reason to avoid the deal.