Hello. New here. I hope this is the right place to ask this question. I recently came into possession of a pair of vintage Heresy I speakers, new in box. Never used. They are a sequential set as far as serial #'s. They have a build date of 1980. I'm considering/leaning toward keeping them for myself. I'm no audiophile, but I would find the best way to use them. I may also consider selling them. Any idea what these might be worth in the open market? Again, they are sealed in original packaging. Never used. I was the first to open the boxes just to look at the serial #'s. Thanks!