Yeah, that was my thought as well. I have a MIM Fender jazz and I was unhappy with it. So my first choice was new pickups, strings, setup, shielding, bridge etc. Was just a tiny fraction of $1600 (though not exactly zero fer sure) and that bass just came alive in my hands.
Now if the mods had not done it, then the next step would have been a MIA Jazz and if then I was STILL unhappy then clearly from there it would be time to move on to new territory like a G&L or MM.
But why not try the upgrades first?
I've already spent a lot of bucks on upgrades. First I bought SD dual core hot stacks for $80 and paid a luthier to install them. I didn't like the sound so I paid another luthier to put back the originals. I've also had a setup done. So I've sunk around $300 on upgrades already. I think it's a money pit. The action was what made me fall in love with it the first time.
