new computer for DAW

so, i've been using the same computer for making music for at least seven years now. it's a totally stripped-down eMachines thing with winXP...only 512 MB ram, but it's perfectly fast and stable (i've never gone online with it). however, i want to finally upgrade my software, and that's going to require more juice.

so basically i want to get a newer version of the same thing. it seems like it should be possible to do inexpensively (is it crazy to think $500 or less?) since i don't need much (here are the specs for cubase 5), but anything i look at where you put together your own components or get something marketed toward DAW-users is $$$. any tips?

hmm, this doesn't look bad: http://www.newegg.com/Product/Product.aspx?Item=N82E16883113140

As a fully paid up REAPER user, those specs to me are o_O

As for actual recommendations, it's down to how much your wallet can stand. But hard drives are cheap so don't skimp on capacity - you might think "1.5TB? WTF I'll never use all that!" but you will use it. RAM is also cheap - max out the memory, it can really make a difference when you have a lot of audio tracks (less important for VSTs).

btw i made my last record on the 75GB hard drive, then deleted a bunch of stuff but i'm running out of space now. i do have a 200GB external hooked up, but i like to save that for backup/redundancy.

I agree on HD and RAM being things good to focus on, though thankfully both of those are pretty easily upgradable if you want to later