I am a cockring addict and have found that the cheapest place to get good quality stainless steel metal cockrings is via a mariners shop on ebay. Do a search for the seller Stainlessdirect (advanced search + then visit their shop) They has various sizes that are only a £1.50 or so. I recommend the 5x35mm or 4x40mm ring for a nice tight fit. Oh and i am not the seller by the way (lol). Just wanted to share the good news.