All right. I have reached a conclusion with my parents, I can get a new computer. Obviously I want to play SC2.
$500 budget.
Every bit overbudget I have to work for, so try not to go crazy.

I have no preferences except that it must be a PC and I do prefer Vista.

You PREFER vista? Wut?

on budget:
http://www.newegg.com/Product/Product.aspx?Item=N82E16834152157
$165 over:
http://www.newegg.com/Product/Product.aspx?Item=N82E16834220735

If you want a desktop, say so, what you have to use towards the desktop, and possibly what you want. If we can reuse a screen, then that gives us $200 more to work with, and I can make you a pretty kickass box for $500.

Windows 7 or XP, don't get Vista.

Vista is a resource hog, and W7 isn't.

New preferences, I'd like a desktop, and I already have a 1680x1050 HP w2207 monitor.
I can also pull out 2 one-gigabyte sticks of RAM from my old computer if need be.
I just said that I prefer Vista. If the computer will be generally less buggy/run faster if it's XP or 7, then fine.

DDR2 RAM?

Probably DDR1.

If you don't want to build it yourself:
http://www.newegg.com/Product/Product.aspx?Item=N82E16883229193 - $600
http://www.newegg.com/Product/Product.aspx?Item=N82E16883229194 - $540
http://www.newegg.com/Product/Product.aspx?Item=N82E16883227261 - $540

I have no idea which of the bottom two is better, that's your job. But these should all be pretty good. They'll run games well (probably not SCII on all ultra, but I'm hoping you don't expect that for $500), multitask, etc.

None of the computers Cent suggested are acceptable by Ex-standards. Then again, 99% of pre-builts aren't.

I can design you something if you feel like building it yourself, but I refuse to recommend any pre-built.

I'm okay with building it. In fact, my dad says he can help me pay for it only if I build it myself.

Edit: The RAM sticks mentioned above are DDR1.

Really? In that case, go ahead with an Ex-build. Probably save you $200 .

If the budget is strictly 500$, I have some tweaking to do, but here's what I came up with:
DVD: http://www.newegg.com/Product/Product.aspx?Item=N82E16827106289
Case: http://www.newegg.com/Product/Product.aspx?Item=N82E16811147135
HDD: http://www.newegg.com/Product/Product.aspx?Item=N82E16822148395 (15$ off promo code EMCYVNY47)
Mobo: http://www.newegg.com/Product/Product.aspx?Item=N82E16813138163
GFX: http://www.newegg.com/Product/Product.aspx?Item=N82E16814141116
PSU: http://www.newegg.com/Product/Product.aspx?Item=N82E16817371016
RAM: http://www.newegg.com/Product/Product.aspx?Item=N82E16820231253
CPU: http://www.newegg.com/Product/Product.aspx?Item=N82E16819103846

$616.23 after tax, shipping, and -15 promo code. However that is to my location in NJ which as a 7% tax. So for you it should be under 600$.

If you need me to tweak it further for a lower price, I can, but right now its a really nice build.

The most I can stretch the budget is about $550, any more and I'll be working for it after school starts.
Thanks Ex.

I had originally planned to not look at ex's build and come up with my own sub $500 build, but it seems that it's impossible to do with a 5770. Sorry.

$68 PSU + DVD OCZ ModXtreme Pro 600W
Thoughts: It's not a god tier psu, but with the combo it's actually cheaper ($18 DVD, $20 combo deal). It has terrible ripple of 80 mV, but the maximum allowed ripple by ATX standards is 120 mV. The real deal is that it works, and it will power your system, and shouldn't kill anything. Ex's Antec isn't a god tier seasonic either, and probably has a ripple of ~50 mV, but is less efficient (I could only find a BP 500 review, so I can't say for sure). You can save $10 by getting the 500W version, or get a 700W non-modular one for the same price (more power is not better in PSUs, and 500W is already overpowered).

$53 Case NZXT EVO mid tower
It's $3 shipping, which is a big plus for cases. Not quite ex's rosewill, but it has a fairly impressive setup. The net result is 3 pounds and a different look. Choose what you like, but I'd only get the NZXT if I could afford the $8. If you want to skimp more, then get any old case. If you manage to find an antec 300 again for $30, then get it. That's the second best deal on a case I've ever seen.

$240 - $20 MIR PSU + OS Asus CuCore 5770 and windows 7
Unless you're going to pirate/obtain an operating system, you'll need one. This particular 5770 is $130 after rebate. If you must drop down to a 5750, you can without much of a performance decrease. There are some people who think that a 5850 is the absolute minimum to buy now too.

$222 CPU, Motherboard, RAM, HDD Phenom II x2 550, asus m4a785, Gskill ddr2, caviar green 800GB AARS
Normally I'd say no to all of these, but considering you're getting them all for so cheap, and I'm still going over the limit by $140, it's worth putting up with some of the crap. A phenom II is a phenom II. You can clock it however you want. I got the cheapest one I could find. The motherboard is a motherboard, which happens to be ddr2. This is a dead-end motherboard, so no reusing old parts here. You'll need a new cpu/motherboard/ram if and when you upgrade. The ram is old ddr2, and only 2 GB, but I have yet to use more than 1.5 GB while editing a whole bunch of files and multitasking a whole lot. Not a perfect choice, but cheap. Caviar greens are a terrible drive to use as your main HDD, but here's the deal: It's an excellent backup/secondary drive. Buy the drive now, then in 6 months save up $50 for a 500 GB samsung spinpoint f3 and reinstall your OS on that.

Total comes out to $640 with tax/shipping in cali (you have to pay tax on it in most states, it's just a question of WHEN and IF you choose to pay that tax). If you cut out the tax and the OS, it's $492.94.

Please don't buy this build just because it's under $500. Look at both Ex's and mine, then make your own decision as to what you want. We're both recommending AM3, 5770 1 GB, 4 GB of DDR3 ram, a caviar black/samsung spinpoint f3 HDD, and the cheapest optical drive you can find. If you can make that fit under $500, then do it. Another idea is to make the cheapest computer you can find with the minimum in quality (ie a cheap seasonic PSU) and see where that build leads us, then you might be able to convince your dad to spend the $700 on that one.

@rockz
Ugh, DDR2? Seriously? :c

That's the only way I can possibly get it under $500 without resorting to a regor and 4770 tier stuff.