OK, take a $550 MIM bass; add a $60 p-up, a $100 bridge, $35 strings, $50 pickguard, $300 (minimum(?) custom paint) gives you $1095. SH sig at $1299 without all the hassle of buying, organizing assembling the parts (and not considering shipping) as a fan.....probably worth it!
Woah, talk about wasting money!!!
If your going to buy a bass and completely strip it down, don't buy a fully loaded bass, and especially not new. Buy a used Squier or MIM, or you can just buy parts.
Here's how anyone planning on DIY should space out the cash:
Alder P-bass body (very good unfinished body from Allparts or Warmoth, or a stripped MIM/MIJ): $100-$200
Maple Precision neck, tinted & with gloss finish (Allparts or Ebay): $200-$300
Seymour Duncan SPB-1 (QP) & wiring/pots: $60
BadAss bridge: $100 (or lower if you find a good deal)
Vintage style long-stem tuners (eBay): $50
Mirror Pickguard: $50
Knurled Chrome Knobs: $5
Paint/finish (StewMac or a hardware store): $20-50
Vintage Fender Precision bass headstock decal: $10-$20 (optional)
Build time: Just a few days. The only thing that would have to be done is paint the body.
Estimated Total: $580-$800... and that's if you want a high quality, exact replica. Then you can use the rest of your money for something useful, like a good case.

