Have a look at the previous Yamaha range - TRB rather than TRBx, BB or BBG5s, Lakland Skyline and Sire range. All good value basses and all lots of bass for your buck. I also like my Squire Dimension which for some reason have become available for next to nothing. Again, a lot of bass for you buck.
Check out YT for "The Floating Thumb" technique - will significantly help with bumm notes. I stumbled with 5ers till I learned this.