To be fair I'm using the ballistix sport 2400 on my b350 pro 4 & it runs at 2933 no issue at all.
The ballistix is good ram & has always been immensely overclockable, I kinda fluked it because it was meant for an Intel skylake build which never hapoened.
I did only pay £70 for 16gb though which is why I bought it.
Back to the question - honestly depends on your location & what's available
Really there aren't any major incompatibility nowadays , there are more expensive lower cas sticks that are guaranteed to run at higher speeds than the cheaper ones.
Generally try & get 2666mhz ram minimum , pretty much any corsair or gskill will be fine.