I know of no legal definition of the term "new". New and unused are different. It's an interesting question, heaviliy dependent on facts and your true, undisclosed, goals. Misrepresentation in sales can be unfair trade practices. Interfering with established contracts for distribution can be a problem.
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I agree with Mr. Doland and would add that the more detail you include in the description the better able you are to defend against a misrepresentation or fraud charge. For example, if you can truthfully describe the article as "purchased new from a major US retailer and never used. In original sealed packaging." Etc., you are better off than simply saying "new" because a purchaser is on notice that the item was previously purchased at retail. I am not aware of a statutory definition of "new" in PA, but under Ohio law regulation of auctions, new merchandise is defined as "not previously sold." I am not an Ohio practitioner so I cannot advise you, based upon these hypothetical facts how your situation would be treated in Ohio. Whether the Ohio courts would reason by analogy and apply that definition to your facts is a question for experienced Ohio commercial counsel. I'd recommend you seek counsel from a local lawyer.
I agree with both the prior answers, "new" means not previously sold in the same channel of trade. What you propose is not "new" but rather "unopened and never used". We are not giving you legal cases and I am not licensed in Ohio. You pay an Ohio attorney for that. Look up "consumer law" under find a lawyer tab here on Avvo
I am not your lawyer and you are not my client. Free advice here is without recourse and any reliance thereupon is at your sole risk. This is done without compensation as a free public service. I am licensed in IL, MO, TX and I am a Reg. Pat. Atty. so advice in any other jurisdiction is strictly general advice and should be confirmed with an attorney licensed in that jurisdiction.