Adobe has long stopped selling CS5 in any form and unless this is some unopened boxed version that has been catching dust in a sheep shed somewhere in the Arizona desert, it is extremely unlikely that it is a valid package and you won't see any support for it nor will you be able to activate it. That and of course whoever might be selling you his upgrade package would have to give you all his previous qualifying versions and transfer the license fully, anyway, making it an utterly moot point whether you actually have CS3 or not. So if you want an hones opinion: This is fishy I'd simply stay away from it for a million reasons.
well, it is sealed and it said 64 bit on it according to the listing on eBay. My friend don't want to pay the price of CS6 or Creative Cloud. That's why she want PS CS5. Do you think the listing on ebay is legit? thanks