In Norway, the mixtrack pro is more expensive than the s4a. try to look for a better deal 😉
I’d go for the Behringer. The Mixtrack kinda gets a lot of  “controller hate” and the s4A is more “pro”
My first controller was the Traktor Kontrol S2, which was a pretty expensive controller to be my first. Anyway, when i paid so much for the s2 (Equivalent to 676$, Norway is extreme), I kinda HAD to spend a lot of time on it! that was how i learned to DJ…
“the comfort of having a good product lasts longer than the comfort of cheapness”
or something like that. 🙂 but when that is said, remember that the gear does NOT matter for being a great DJ! 🙂
Keep spinnin!