Sorry guys - I do have to work for a living, and its hard to keep up here, sometimes.

#1 - Melikia, you DO want a power supply in the 850-1000 watts range, anyhow, ... for the kind of hardware you're talking about. You always want about 150 more watts than the minimum or the expected demand on the system - its what gives your computer the lifespan it should have. Protects your investment.

OK, there are some things you can do yourself, without almost any hardware knowledge or skills - that will save you money.

For example, you can insert your own memory sticks into the computer's motherboard with no worries - a "no-brainer." And, since memory is really, really cheap, you can purchase the minimum necessary now, and plan on picking up more later. [ edit - RAM is just a couple hundred dollars for 8-16 GB, depending on what  you get. For example, for your system - a pretty high quality RAM of 8 Gb is just $130 shipped at no cost from Newegg, if you are in the USA.] )

So, buying less ram now for the tradeoff to a great video card is well worth the tiny little effort it would cost you.

There are just two things to keep in mind regarding RAM. The most important is that all the RAM in the motherboard must match. (And second, there are some little quibbles about "quad channel", but it is easy to deal with that when the time comes.)

So, my personal advice for staying on a budget would be to go for the great video card, and take less RAM for now.

Another possibility is to ask Alienware what it would cost for the box with no video card. A video card also is a thing you can insert into your motherboard yourself with no worries to it.  You could get whatever you want now in the way of the box (sans video card), and then purchase the Gigabyte 570 for around $350, or the Gigabyte 580 for around $535 from Newegg.com. No tax, and no shipping cost if you are in the USA (and not in California - regarding the tax.)

Both cards would be great (absolutely wonderful) for several years. They are not the 590, but they are great cards, and at the cutting edge of the technology right now.