picked up a pare of mufflers a while back for a project that got changed

they are 3013 boss 302 mufflers. don't remember exactly what I paid for them and posted them back for sale probably asking too much but figured shoot high and accept a lowball.
had some peole asking but no solid hits, then i got a msg from a guy saying " just want to let you know that the Boss 302 used the exact same muffler as the GT and is not an upgrade". he said thye sell for 100 bucks a pair on the forums all the time.

just wanted to be sure did i get hosed? it wouldnt be the first time i was cotacted via kijiji to have someone tell me what ims seiil is garbage with teh hopes ill let them have it cheap