I am building a new computer to last probably 2 years. Two years because technology moves so fast it will be average to below average compared to what is the norm for the average new computer. I will either use the new bulldozer CPU or high end six core that is already out. Two mid level video cards to power my quad display. I want to build my computer using high quality parts but am finding it hard to justify the difference in a $50 PSU to a $150 PSU. Please help me understand how one can be worth 3X the other.