It's kind of a big difference between the Kit Scratch out and the TW Red compound.
The big 14oz bottle is certainly enough to do a complete car, especially if you have an electric buffer.
I think it's kind of weird that they call it scratch out, when its really so gentle that it is not very good at removing scratches.
I'm not sure which Turtle wax you like to use, and in what form (paste/liquid), but the TW Ice is their most high end product.
IMHO Once you use the liquid polish, and realise how fast and easy it is (since you can use it on chrome/plastic/rubber too, and it doesn't leave a chalky residue on the edges of body panels) you'll be hooked.
It's much cheaper than it looks, since you need maybe one shot glass (1.5 oz) to do an entire car. So a 16oz bottle is maybe 10+ applications. It may take 40 minutes or less to do the entire car depending on your working rhythm.
I'm a huge fan of the entire TW Ice product line (own pretty much all of it except for the Tire Shine and Ice paste). The Ice spray is very "light" and more for cleaning up the car, or giving it a "top shine" vs protecting the paint.
If you keep a bag of microfiber towels, and Ice spray in the car, its very easy to keep the car looking awesome by dusting it off as needed. As usual, frequent car care is easy car care!