3-4 K for a bass.. and you say non boutique....??.. thats not sensible money, thats top end scratch....well there are 4 names that spring to mind.... Suhr or early Pensa jazz basses, imo the best jazz basses in the world.... Sukop 4 and 5 strings.... STR are just EPIC basses, if you have played a Fodera, these are just as good but cheaper but lesser known... and the brilliant Xotic jazz basses... Amp wise Bergantino or Aguilar are worth a try....