I have a Fernandes TEB-1 bass with a passive P/J setup. When I asked Fernandes what kind pickups the TEB-1 has, I was told it had "A set of our (Fernandes) own P/J pickups" which I can imagine is not the best pickups on the market. As I am not too happy with the sound of the bass, I am considering getting some other passive pickups. My quistion is how much this will improve the sound, as the bass itself is not a very good bass. (about 5000 NOK, or 500 $) Is it stopid to put pickups for 1500 NOK in bass worth 5000 NOK? At last; my teacher recomended replacing the passive pickups with active pickups (passive electronics). More expensive, and even a bigger waste of money?
If the sound of the pickups isn't the only thing you're unhappy with, I'd say save your money for a better instrument. If you think new pickups would make the bass worth keeping, you could at least try changing them - any decent music store would let you return the pickups if you're not happy and give you a full refund.
I have an old Washburn bass that has a body made of plywood. The original pickups were weak and noisy. I put a SD SPB-2 "Hot for P-bass" pickup in it, and it sounds fine. I use it when conditions are a little iffy. I'm generally the only one who knows I'm using a cheap bass. I think your Fernandes is probably a better bass than my Washburn. If the playability is good, and the sound is OK, it might be worth doing. It's kind of a personal decision, though.
I toyed with the idea on a Squier P Affinity. The action etc was excellent and it was a nice bass. But, as someone pointed out to me on TB, at the end of the day it's still only a Squier. I've no problems at all with those basses but, on balance, it did seem a waste of money to do the mod. So I didn't and sold the bass instead. I think I'd save the money and put it towards a better bass. John
Your best bet is to get the better bass, but I do have an alternate suggestion. If getting good pickups is in your budget, while the bass is not, you might consider putting the good pickups in the bass you have. If you ever sell that bass, put the originals back in, and hang on to the good ones. You may find a good use for them down the road - like putting them into a new bass.
You may be able to find some used pickups as well. I put some MIA Fender Precision pickups in a MIJ Fender, and it sounds pretty good. I don't know how many local guitar shops there are in Folldal, but maybe you can find a shop that will ship to you. I got my MIA Fender pups for $29.99 USD, but of course that was from a shop here in the States. Like I say, I don't know anything about the market in Norway, but it might be worth a look.
I put Seymour Duncan Hot Jazz pickups in that same bass and it sounded great. I also tried some EMG's and didn't care for it. Too sterile, but that might have had something to do with the body wood.