I sent him an email and he replied that it is a legal copy, but that local merchants will say it isn't so that they can sell software. Doesn't make sense.
I filed a complaint with paypal and he issued me a refund in under 2 minutes. Well, at least I got that back, but this burns me.
The link to the auction is below, in case anyone is interested. I should have read it more closely and suspected something when he said that it wouldn't work online.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=320258581799&ssPageName=STRK:MEWN:IT&ih=011
Thanks for your help. I'll buy a legal version. I have the 2006 with add-on, and it's a wonderful simulation!