Sorry, but this list, the Yahoo one, eBay and Clausing are your four best chances for any parts. Clausing's pricing policy is apparently based upon what the part is on the books for. So if it's a slow moving part that they last made a batch of 30 years ago, it may seem fairly cheap. If they made it or had it made withing the past 5 years, it may seem expensive. But that's just what things cost these days. Price the nearest equivalent plain gear from Boston and add some $120/hour machining time to that.