I find that punk is more in your EQ (emphasized highs) and attack (REALLY HARD!) I think it was Flea who said that the punk mentality when he was growing up was: upstrokes are for pussies 
You can EQ any bass to sound punk, though a beat up bass definitely LOOKS more punk, and IMO post 9-11 punk is as much about the looks than tone or the mindset.
and a bass that usually sells for at least a grand new, a stingray might not look as punk as you want it to.
so assuming that you've got the cash, find a beat-up p-bass (preferably a squier) on craigslist, put some hot pickups in it, and use the rest of your money on a DI with a built in EQ.
Now scratch the hell out of the bass, put stickers all over it, throw it down the stairs and snort some heroin off of the back of it, and you will be well on your way to sounding punk.
also do you have a mohawk yet?
get one, a.s.a.p.

You can EQ any bass to sound punk, though a beat up bass definitely LOOKS more punk, and IMO post 9-11 punk is as much about the looks than tone or the mindset.
and a bass that usually sells for at least a grand new, a stingray might not look as punk as you want it to.
so assuming that you've got the cash, find a beat-up p-bass (preferably a squier) on craigslist, put some hot pickups in it, and use the rest of your money on a DI with a built in EQ.
Now scratch the hell out of the bass, put stickers all over it, throw it down the stairs and snort some heroin off of the back of it, and you will be well on your way to sounding punk.
also do you have a mohawk yet?
get one, a.s.a.p.