bloodfist, you're going to get booked for that.
If you've got 600 US and no amp, i'd suggest getting used gear.
If you can find a Made in USA Peavey 100 watt 15" workhorse, get it. This things will make it through beer spills, drive by's, tornados, nukes, etc.
that should leave you with AT Least 500 bucks to get a bass. And if you buy used, you'll get a lot more bass. For example, you can get that Sr505 ( not sure how much it is in the us) and have 0 cash left over. If you decide to sell it at a later point, you'll lose around 200 bones of the original price.
options B: You can find that Sr505 used, for a lot cheaper, and get a little better amp. If you keep the Sr505 in good condition, chances are, you'll be able to sell it for the same price. (it might take some time though)
Option C: You can buy a Used carvin. These things are made in america and are sweet. Neck through (most of them), active pickups, and good wood. Again, if you keep these in good condition you can sell it for what you bought it for.
Option D: Keep checking the TB classifieds, craigslist, kijiji, ebay. You should be able to find a great first bass for 500 --600 US.
When i got my second bass brand new, i kind of regretted it. Sure it was fresh. But i thought about it, and for the money i spent, i could have gotten a nicer bass. But oh well, it still works and sounds great.
Some more advice. If you think, screw the amp, ill get one later, think again. A crap bass through a good - decent amp will sound better than an amazing bass through some "mikrovox tube 10 series".
And if you do decide to buy brand new, if they're offering you a generic case, screw it. Those cases are cheap, and are always almost 80% profit for them. They make it out back with cheap plastic and latches from home depot. Actually, i'd recommend getting a nice gig-bag. A nicely padded one. They last long, are light, and will do a good job protecting your bass as long as you're not careless.