I'd never buy an option to improve the resale value, because this will rarely happen. In general, options depreciate much more than the base vehicle. People will say they want x and y, but in the end many will opt for a vehicle without these to get a lower price. They want them, but they don't want to pay for them. You won't get anywhere near $4,000 back when you sell the X5.

That said, I'd personally go with the sport package, but then I care a lot about handling. It depends on your personal priorities.