I am just an amateur photographer, and am looking to buy a gift for a friend. I believe he has a Contax 640 (or maybe its 645 ?). I was searching on ebay and found these ... http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=270608286193&ssPageName=STRK:MESELX:IT Is it true these will fit any model Contax camera ? Are these straps really worth $70. I had seen one selling on ebay for $120 (and it was used). This guy says his are new and were never used. Thanks !