Linking is probably not going to find you a system that priced. Companies need to make money. You can easily build one for that price. You would need to contact a local computer shop or find a good friend that has actually assembled machines before.
However, CyberPowerPC makes some decently priced systems. With any large company, if it does not have a dedicated video device (i.e. nVidia Geforce ____ or ATI Radeon ___) DO NOT TOUCH IT. Intel integrated and AMD's onboard nonsense will NOT run anything near current at anywhere near reasonable.
-Hate