If the number is registered, it's registered. You won't be able to play online or receive updates. I don't condone piracy, but you might as well acquire the game through other means than purchase it through eBay. If someone sells their game on eBay they're still able to play it online, and they get a partial refund in effect...so no, definitely don't buy from eBay!
Thanks for the reply! I am not buying from ebay, I was merely curious how this would've worked. I see how this works now, definitely not in the buyer's favor. Seller still gets to keep his/her game through impulse, makes a profit off of the person he/she is selling to, and on top of that since they're probably still registered, the buyer couldn't access online.
Screw that. I admit there are some great prices for the game on ebay, but I'd rather hand the money to the developer and I don't want to take any chances either, either way. Thanks for letting me know.
I'm tight on cash at the moment and still don't know when I'll be able to afford the game. I loathe piracy, so that's not even an option and besides, I like the updates Stardock hands out. I guess I'll just have to sit tight and wait, as hard as that is... I want this game so bad. 