I don't have time to right now, sorry, but I'm guessing some people are turning this "challenge" down because your asking for alot for that amount of money. A monitor will run $100, a printer will run $100-$200. That's already half your budget. Include the mouse, keyboard, OS, and your already easily over $350.
That doesn't even include any of the internal computer hardware.
If you strectch your budget to somewhere around $800-$900, or take out the printer, then the "challenge" would be a bit more realistic.