Right on, Zav. Determining value is exceedingly difficult, for sure. Things are worth what someone will pay for them.
I'm not sure if you're on the buying or selling end of this question, but I can assure you that the CNT is one of Weber's finest creations-- a truly useful tool that does an incredible job. It makes corn a true 'set it and forget it' proposition. And the ring also allows you to do multi-tier cooking on a 22-- just add an 18.5 grate to the top of the CNT, and you're cooking on a whole new level.