Unlike the CPU, motherboard, video cards, even RAM; a power supply and case are items that will not become obsolete as soon as you open them. You can use a power supply and case for years and over many upgrades. Never cut costs on the power supply, because when a poorly made one blows you loose more than just that component. As for the case, these things are rather large objects and can be difficult to hide (poorly designed ones are can also be noisy). Unless, the house is decorated in a faux medieval steam punk fashion, a simple neutral design is the best bet. Before you make a choice on a case, always look for pictures of it (other than those of the manufacturer) .. as they often look way worse in real life. As far as computer builds go, I would rather spend $700 on something I am going to be happy with, than $550 on something with weak components.