I would only question where the seller got the copy. Selling for hundreds less, he's either taking a bath on the sale, or it's not legit.
http://forums.adobe.com/message/1636890 warns about buying from eBay
I agree with Jim... find out why the item is "hundreds less"
>They are hundreds less
Hmm... does that mean this person is the "they" that selling one for hundreds less, or "they are" means multiple copies?
Go for it mate, should be fine.
Welcome to the forum.
How many copies does this seller have?
Could they, or shills, have posted all the great comments on them?
Adobe will support legit software, but one does not often see legit Adobe software on eBay - usually pirated, or perhaps an upgrade, where one would need the proper S/N from their upgradable version.
Good luck, and if you are one of the very rare people, who has actually found legit Adobe software on eBay, happy editing.
Personally I'd stay away...