There's one one market place for I think 350 I'm like dam I wish I wasn't broke
And that, my friend, is what we at TalkBass refer to as GAS-pain. GAS= Gear Acquisition Syndrome and the pain of wanting a piece of gear but still gotta pay the mortgage, bills, etc.
That's a big reason why I'm a "gotta try 'em all" string-GASer. Because strings are the cheapest and easiest mod to make the most dramatic difference in the tone and feel of an instrument.
I often feel like when chasing "the" tone and copping the gear our idealized player uses... I never quite get there. But when I alter a little something-something there that my body and soul says, "Aww yeah!" to, I feel like I get closer. It's not exactly "idealized player's" tone but it's my version of it. Kinda like how I will never duplicate my mom's chana masala (a chickpea curry from India) but I'll still get a damn tasty one. And some people might like my cooking better than my mom's.
So I will say, if Fieldy and that style of music is an influence, start with 5-string bass (budget 5ers with good low B strings is easier to get than when I was starting out), throw on some stainless steel strings (maybe some DR Lo-Rider steels or DDTs), tune down a whole step (BEADG to ADGCF), and play with your amp's EQ settings. Fieldy's scooped mids might not work for you/your band, but Ryan Martinie (Mudvayne)'s boosted mids tone might work. Both slap and pop in bands with heavy downtuned guitars.
What I respect about Fieldy and what makes him so cool is that he has a voice that's distinctly his. You hear his playing and you immediately know it's him. So why not try and be cool like that and discover YOUR tone, YOUR sound? My body and my touch are different from those of my heroes, so I want to be my best me. I feel like any bass I pick up, I sound like myself. I pick up a Fieldy K5, I sound like Dincrest on it. And if someone else picks up my bass, they'll sound like them on it.
(And go figure, some of the most lauded bassists like session god Leland Sklar don't really have a signature tone. Like, Lee Sklar's tone has to be as neutral as possible to fit the myriad styles of songs he plays on. But maybe that's his voice- the one that fits everywhere).