Cas (CL) is one of the primary timings. It's the delay time between when the memory controller says it wants data and when that data is available. So the smaller the CL, the shorter the delay, the faster the ram actually works to get info moved.
If 3200/16 is normal, 3200/14 is faster. 3000/14 is a hair faster than 3200/16, 3466/17 is a hair faster than 3000/14. 3466/19 is slower than all the above. By a hair or 2. The delay is too long compared to the speed it can work.
When you consider that all the above is worked in nanoseconds, the differences are extremely small, to the n_th degree but translate to only a few fps difference. Maybe.
Price is due to binning. The looser (higher) the timings, the more impurities are in the silicon. Binning for better silicon ups the price. CL 17 can easily be loosened to CL 19, but there's no guarantee CL 19 can be tightened to CL 17. Same for CL 14/16.