150$ Budget, Cheaper the better!

I'm buying a new system for my little sister, mainly for casual internet surfing somewhat fast.

Approximate Purchase Date: (Sometime this week...)

Budget Range: (150$)

System Usage from Most to Least Important: (surfing the internet)

Parts Not Required: ( Keyboard, mouse, monitor, speakers, OS, Case, HardDrive, CD ROM)

Parts I NEED : ( Motherboard, Processor, Memory, Possibly a power supply)
The case I'm using is : http://www.thermaltakeusa.com/product/chassis/fulltower...

I'm browsing around this area :

http://www.newegg.com/Product/ProductList.aspx?Submit=E...

http://www.newegg.com/Product/Product.aspx?Item=N82E168...


(OPEN TO ANY SUGGESTIONS!!!)