Additionally, those with more specific computer needs usually appreciate being able to upgrade certain components to fit their needs and the evolving needs of the software being used; in a typical manufactured PC the support components (such as power supply unit, motherboard, or even the chassis) are unfit for accepting high-performance add-in components. Constructing a system with future expansion in mind allows for such upgrades, which in turn are much cheaper than buying a brand new computer every time individual components become obsolete or insufficient to meet the needs of the user.