This Autavia was on the german eBay site a few months ago (I think it was September) and "sold" for a similar price of 1800 Euro at the time. I don't suggest getting all worked up about it, because this was one of those deals that is more than likely a scam rather than an naive seller who did not know the value.

At the time, the watch was listed on eBay.de, and was only allowed to be purchased for shipment to a buyer within Germany. I thought I had saved the link, but I am unable to find it at the moment, but I am 99% certain it was the same exact watch. Either way, I think this guy is trying to pull a fast one on someone, so don't beat yourself up too much about "losing" out. I know it's easier said than being in the situation, but thought this new info would at least help you cope with the loss.

:
: http://www.ebay.de/itm/Rare-Vintage-Heuer-Autavia-Military-Men-039-s-watch-/112233821992?hash=item1a21a83728%3Ag%3AYRQAAOSw6DtYTWuE&nma=true&si=VXK3hsK9mz3UFe2egZ7ljn5CU7E%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557