Slight problem with the budget

Do you remember when I said that I promised to build my wife a new computer?
Well, she certainly does.
It turns out that they don't make the pretty blue case anymore. So she has picked out a different case, which came in the mail yesterday.
I already have an extra motherboard around here. It's a very nice one.
Now she said that she fully expects the rest of the "computer guts" to get here soon.
It's really hard to stall her any longer. She saw 7's computer before I mailed it off. "Now it's my turn. You can build 7 a nice computer. You can build me one."
For those of you that don't remember, here's 7's computer (early photo):

She tells me that it doesn't have to have four screens, but it needs to be "at least as fast as his"
Ok, that sounds fair, right?

OUCH!

Does anybody around here do computer specs?
7's computer has an AMD athlon 64x2 4800+ processor with 4GB RAM.
It has A GIG of video memory. Photoshop will crash before it crashes the computer (speaking from experience).
7's computer was built for the purpose of doing extremely high end photo processing and graphic art work.
My wife wants her computer to play SIMS.
"So why do you want it that fast?"
"Because you made 7's that fast."
"Mine's not even that fast."
"We're not talking about yours."

Now the easy way out is that my wife knows NOTHING about computer specs.
But I cannot lie to my wife.

So what to do?
Somebody throw me a clue.

I might have to bite the bullet and come up with some high end computer parts here.