Hands down best p bass value is a preloved MIM classic 50s. Should be able to find one for around 500.00 in excellent condition. Slap on a set of flats and you're there. Don't even need to change the pickup.
I have bought two modded MIM jazzes for around 500.00 each that sound and play killer. One has SCN pickups and is passive, the other has a East pre amp and Di Marzio
js.
Found all of these shipped for right @ 500.00 each with hard shell cases and couldn't be happier for what I have invested-actually couldn't be happier @ any price because the feel, the sound, the look of Fender TO ME defines electric bass.