If you observed the Extreme Pro is in fact faster than the Extreme than that does answer your question (it answers the faster part, we already know the cheaper part).

If you have both cards you can always run a test, just set the camera to burst mode and hold the shutter button - this will tell you the maximum burst length for each card, or, if you don't care about that, use a stopwatch to see how much time it takes to do something you do care about.

After you run the test, assuming the Extreme Pro is faster, you can decide how much you are willing to pay for the speed increase - and if the extra cost of the more expensive card is worth it to you.

By the way: 3 related things I learned during my 15+ years as a software developer are: 1. for any reasonably complex system (like, everything) you can't guess performance by using specs - you have to test it, 2. at some point the difference between the "fast" and "faster" systems is so small it's unnoticeable - at that point you can decide the slower system is good enough and go spend your time/money elsewhere and 3. the point the system is fast enough can change radically depending on how you use the system.