All of you sound very experienced with Elna. I need help. I have a chance to buy a 2001 Elna 634 Serger that is in really good shape. Original box, manuals, accessories, and extra thread. I have seen the original invoice and it said sale price $699. Would anyone know how much this is worth, or suggestions on what I should offer. This is my first serger, so don't know much about them.