No cause for depression! I believe Wiztecy is right, that you do have the right to back out if the car doesn't measure up to the eBay ad. Check out the eBay Auto terms, get a CarFax report, and go with your eyes open. There is a Tesla service center in Vegas (6260 W Badura Ave, (702) 914-6500); a call to them might confirm the car's overall status (clean, salvage, etc.), though I think they are being more tight-lipped these days due to privacy concerns.
If nothing else, you'll have a fun weekend in Vegas, and have learned a bunch about what to look for in a Roadster you will want to give a new home to. Each Roadster, possibly more than any other car, has a unique personality, and needs a matching owner. This one may not be the one for you.
Welcome to TMC,
@medfly21! +1 to what
@gregd stated above as well as the other sage advice folks have given you. Hoping the eBay terms are in your favor and you're able to back out. If not, since it seems you're still planning on flying to Vegas tomorrow, you have one roll of the dice left.
The eBay auction states that the car "...has had all scheduled maintenance..." which seems to intimate that its annual service has been performed regularly at a qualified Tesla SC. If this is indeed true and the recent service records show work performed by/at a Tesla SC in the past year, congrats, the car is not blacklisted! However, you'll need the actual records to know for sure. Was the seller able to provide any factory service documents? If so, let us know what they say and we'll help provide some addl. provenance on the car. If, however, there are no service records available...
...contact the Vegas SC ASAP as suggested and inform them that you've flown into town from out of state and have a Roadster that urgently needs a factory PPI and Annual Service performed on it. Chances are you'll be speaking with a Service Concierge who'll request the last four digits of the VIN. Politely ask him/her to do a quick check in the Tesla database to see if there's any past service history on it they can share with you. At this point, your fate will be in the hands of Lady Luck. Fingers crossed (a) the car's not blacklisted and, more importantly, (b) they can accommodate you to perform the work on such short notice. Ideally, the PPI will be rolled into the cost of the annual housekeeping which will set you back another $600+. However, for all the knowns and unknowns about the car, this will provide you the best peace of mind $$$ can buy.
As far as getting the car home to SLO, unless you have a few days, a full compliment of charging adapters, and the EVSE/Plugshare gods are feeling generous, it would be prudent not to push your luck any further than necessary. Even assuming everything checked out at the SC, a 400+ mile drive across the Central CA desert at the height of summer heat in an "old" EV isn't advised. Do yourself a favor and rent an ICE pickup + one of
these for your journey home.
While it would have been better to have done your research before committing to the purchase, I truly hope everything works out for you! These are indeed very special cars so if the stars happen to align for you with this particular one, that's one less Roadster orphan in the world which is all right in my book