If I purchase wholesale (new) Aeropostale clothing from ebay, can I legally resell them and advertise them as new, never worn?

It doesn't matter whether you bought the name brand merchandise from ebay or the back of a truck in a dark alley. You need a license from the manufacturer/holder of the trade mark before you can sell their merchandise. You would be looking for trouble to use the trademarks in advertising. These national brands spend a fair amount of resources protecting their marks, which is something the law actually requires them to do.

This answer is provided for informational purposes only. Actual legal advice can only be provided in an office consultation by an attorney licensed in your jurisdiction, with experience in the area of law in which your concern lies.

You can't use the trademark of this clothing maker without unfairly competing with them. It's very likely that even if you used a disclaimer that the Aeropostale trademark is owned by that company on your flyers, cards, website, etc., their customers would be confused as to your affiliation with the clothing maker and might mistakenly buy the clothes from you instead of from the trademark rightsholder or its authorized dealers/retailers.

Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.