Just to spit into the wind one more time:
I'm a professional computer programmer who has tons of crazy home DVR and automation stuff going on. I haven't spent more than $500 on a new computer since the year 2000 (I got a $500-ish desktop then, a laptop for about $450 in 2004, my current laptop for a similar amount around 2009, and a new desktop for about $550 last year).
They're almost all overpowered for any real business/programming needs. If you aren't gaming, almost any low-end off the shelf machine (desktop or modern laptop) at Best Buy will be more than powerful enough, even if you have significant business needs, and you'll be way happier with that $500 machine and $500 worth of fun peripherals (Sonos home automation or Harmony remotes or whatever) than you would be wasting money getting a $1000 computer with a discrete graphics and sound card that you will quite literally never actually use. Hell, the $400 shitbox with a sweet huge monitor is a much better use of funds for most people than the $700 machine with a crappy $300 monitor.
If you need big gaming power at home then that's a whole other story--you can spend arbitrarily much on a gaming machine. But if you're not into cutting-edge gaming, most of what Couperin and people are advocating here is far, far more expensive than what you'll want for a home machine. And that home machine probably does more than most non-gamers could even dream of. Spend the extra on cool peripherals (speakers, controllers, Harmony remote, whatever), don't overspend on the computer itself when that's basically just money you're flushing down the toilet never to see any return on.
Now, an SSD is definitely worth the money, whether you're a gamer or casual home office user. That's an absolute no-brainer.
EDIT: Basically, unless you're a gamer you should get yourself a pretty cheap commodity machine but with an SSD, and spend the rest of your budget on a decent monitor, speakers, home automation crap, and other shit. Dumping that money into the computer itself is a stupid waste that you'll be repeating shortly and won't get a real benefit out of in the meantime.