Re: Permission to ask a COMPLETELY off-topic question…?
Simples.. your third paragraph about costs explains it all. Telephony cables use one of (I'm thinking this right...) 3 sizes only of connector and all the commercial connectors are for that particular cable which is a standard. Even the connections are standard. The round stuff.. not so much standard anymore as connectors (especially in AppleLand) are proprietary. Plus many of the round ones have shielding.... it's tough to shield a flat cable economically.