I had both. TZ is still here. Sold CV ages ago for peanuts compared to what they sell for now.
Personally I think TZ is a MUCH better game. CV is fun, but evetually gets old.
In terms of game play, I think TZ is better. In terms of price, I think CV sells for more. I could be wrong here as prices seem to change daily. I think a nice TZ is in the mid-$5k range while a nice CV starts at the $6K range. So if they are the same price, I think the better "value" is CV. TZ also comes up for sale more often...at least in my past experience.
So end of the day, you need to decide what is important to you. "Value" or game play.
Cheers,
Duane