Let me tell you by experience that it's MUCH better to check the car personally before closing the deal. I know you're doing just that, but wanted others to know it's not worth it. I recently made the mistake of buying an expensive car trusting the dealer, mostly for the inconvenience of the trip (plus saved a grand), but it wasn't a pleasant transaction. I'd have probably bought the car anyway, but man, do I hate surprises.
Having said that, if you take the trip to check the car out, it'd be a lot cheaper and quicker to just drive the car back than shipping it. And you're already there. I did that with my M3, and drove the car home 780 miles from Vegas. I got there late, so ended up getting home at 11pm. Any more distance, and I'd had stayed somewhere.
In your case, with 1,000 miles, you'd have to do it in 2 days to be safe. Either get there in the afternoon, do the transaction, and leave first time in the morning, or get there early and get a head start on the trip back, and stay somewhere about half way. I'd do the latter for sure, BUT I'd also extend my trip a little bit by traveling nice secondary highways, which can be a lot of fun, and you can usually travel faster as well (less patrolled). You don't have that luxury if you plan to do the 1K miles the same day. Good luck.