I would recommend first deciding what size and type of hard drive, memory and processor would suite your needs. Then begin looking for a computer in the price range that meets your needs.
I prefer an i5 or AMD processor equivalent because I have many tabs and programs open at the same time. I can be entering up to five different reports at the same sitting.
My experience with discounted good computers have been with: Frys, Micro Center and Staples. I did buy 10 Black Friday computers back in 2010 when a glitch allowed me to purchase online for pick up at the store at the Black Friday prices. Since then I've had no luck.
I run my computers into the ground. Usually the hard drive fails and I get a new one. I have an Acer that I picked up from Micro Center for $341 and got two years of Office 360 for $50. I have a second Acer but it does not have the speed. Just picked up A new Surface Pro 3 with Windows 10 for $250 so I'm getting used to it. I want the cover for $50. Had to settle for a keyboard for $22. All new.
Do not read so much, look about you and think of what you see there.
Richard Feynman-- letter to Ashok Arora, 4 January 1967, published in Perfectly Reasonable Deviations from the Beaten Track (2005) p. 230