The bad thing about the laptops and other electronics is they are display models or returns. You don't know how they were used before you get them. I'll bid on one when they come in sealed boxes, discontinued. My 39" Haier tv was $170. + 10% and tax no box. If I get a year or more use out of it I'll feel good.
If you go to a food auction watch for items to be close to or out of date. Mother bought the bigger than quart size jar of mayo or salad dressing for about half of store price, had 2 months left before expiring. A pint of mayo will last me a year or more, so I wouldn't buy it.