Like MatrixClaws specs he posted, you should be able to get something along those lines for under 1000$..
Some things to add in the discussion:
A good motherboard and processor is what to invest in foremost, make sure you get a motherboard with Sata3 (6GB/s)..
I recommend an Intel CPU, ex. the one MatrixClaw mentioned..
I have the 3570K clocked to 4,2Ghz..
It's way better than the AMD FX-4100 I have on my other PC.. that's clocked at around the same speed..
An SSD is not really for storage, it's a drive you put stuff like OS and software to get them to load faster..
I've got a 120GB SSD for just that, and (not extremely necessary) another 120GB SSD for Samples that I want to load fast..
You can boot up in just a few seconds (10 seconds or less) and get to work, software starts basically in an instant as well..
Get a regular HDD with longer warranty (ex. Caviar Black), they're not much more expensive for the quality you get..
I have one HDD for storing music-files and projects, and another HDD for junk, installation files, some samples, mixing articles, etc..
Go for a 64-bit OS, I use Win7 (just a preference) and you can easily use up a lot of RAM..
I've got 16GB of 1600mhz RAM, not the fastest but good enough.. I use 4GB of it as a RAMdrive, basically really fast storage, way more than an SSD..
I use the Ramdrive for misc stuff like tempfiles and as a scratchdisk for bouncing/rendering..
And it's not a bad idea to futureproof your setup in case you get some software that's really RAM-heavy..
I'm assuming you live in the states so this would be way cheaper over there:
http://www.inet.se/kundvagn/visa/3250292/2013-04-19
6995kr = 1075$
You can also get some parts used, like the case and powersupply..
The onboard graphics on the CPU can play modern games on low/med-settings..
I've got a Radeon HD7770 for my other computer that is worth the price, can run a lot of games on max-settings..
Intel will be releasing their new Haswell CPU soon, might want to save up for that..
CPU and Motherboard is hard to futureproof now that it seems that the computer companies are going to combine the two..
And down the line we have the memristor and other innovations coming..
If you're in a tight spot with money, AMD is not a bad route to go, it's just not as fast as Intel.. but you get bang for your buck..