I replaced the stock pickups of my Ibanez Mikro with a pair of P/J Geezers, even if the pickups costed me nearly as much as the bass had cost me from new.
I knew it was worth it though since I loved it's playabillity and it sounded good unplugged.
If your bass has good playabillity and it sounds good acoustically then a pickup upgrade should improve it significantly, as chances then are then, if it is a cheap bass, that they saved production costs on the pickups.
I know at least it improved the tone of my Mikro significantly.
The P pickups went from decent to amazing and the J pickup went from weak and thin to, well, amazing as well.
Got so much more clarity and definition as well as some added punch out of the swap.
And it was all worth it.
In fact I never owned a bass I love playing as much, and now the tone of my bass match it's playabillity.
Good choice, EMG's Geezer Butler pickups sound astonishing, and even if it seems like everybody is using them these days I can't say I blame them, I don't mind to maybe sound a bit like everyone else at least, if it gets me the tone that I truly want
And they certainly hit spot on!