Putting together an extreme budget build for my girlfriend's parents. Probably around $300-500 range (not including monitor.) Will be purchased very soon. In terms of usage, just a lot of Web and Videos etc., no gaming.
Preferred websites to purchase from: Newegg and TigerDirect
My main advice is don't go anywhere near that cheap power supply, from tiger. The Rosewill one's OK, but would suggest Antec Basiq BP430. Good quality budget PSU, plenty of power if you're not going to stick some powerful graphics card in. If you're not into gaming, as such, you don't need a seperate graphics card. It may be worth considering using i3-3225 processor which has much better onboard graphics, making it less likely you will need to add anything.
What os are you going to be running? I noticed you did not include it is it that you already have the os? If you gonna be shopping around for the best prices i suggest using http://pcpartpicker.com/ it may save you a few more dollars here and there.