What would scare me, even if everything looked legit, is the possibility that the instrument was severely damaged, like from a drop, and had been repaired. It will look purty and everything will work, but total stations are like cars - once they've been wrecked they're never the same.
Have bought a couple of stations of ebay. Most importantly is buy the seller. As in know who is selling you the products, Make sure it is not stolen goods and know the details of the products. This helps gives you a rough logbook on the details of the total station similarly to the car. Secondly always ask for pictures! Pictures is harder to lie if you ask them to take with todays newspaper in the background to accertain its his picture and not grabbed from the web.
My apologies for the length of this:
I purchase all my instruments used. Like cars there's a premium to take the new off. I love my dealer of which I only have one within 5 hours drive. If he has what I want I will buy from him KNOWING he will stand behind it. However, he doesn't always have what I need, then and only then I will go to ebay.
I have gotten deals on all sorts of items from ebay. By 'deals' I mean 75 to 80% of what it would cost if my dealer was selling it. If it's lower than that it's a scam.
Three keys are:
1) Use the rating and feedback info with special attention to transactions as a SELLER.
2) Ask questions. For survey instruments I ask:
Why are you selling? I actually ask this question about everything. The answer, more specifically the WAY it's answered, usually tells if the guy is REALLY selling because Grandpa retired from surveying, but doesn't have an ebay account. Try to get the phone number of someone who actually used the gun.
When was it calibrated, and by whom?
Is the case with it and is it correct for the instrument?
What year is it?
How are the batteries? (re-celling batteries quickly runs into a few-hundred bucks)
3) Require the product to work the day it lands at your doorstep. Non-DOA is the ebay lingo. After that you assume the risk.
People doing a lot of selling on ebay want to keep their rating high with good transactions and happy customers.
Folks that steal stuff cannot answer the questions, unless they themselves are experts on the product-very rare.
People that ship DOA stuff portrayed as working will quickly cost themselves their ratings if they don't take it back.
How does a seller know their product is non-DOA if the batteries don't work? Or if they don't actually use it?
Ebay is not for the eternal optimist. If you can think of several face to face transactions that went south on you for cars, boats, baby strollers, whatever then stay off ebay. To put it bluntly, you're a mark and ebay just makes it easier to be taken advantage of.
Steve