Used guns can be a great bargain, but while they have been weathering the test of time, they have also been getting someway along the line to wearing out. If someone isn't confident they have the ability to judge how much useful life there is left in a particular used firearm, they may be better off buying a new budget rifle. The peace of mind that comes from a manufacturer's warranty can be valuable, and with advances in technology, even these budget rifles may be better than Remington, Winchester or Ruger was when it was new some years ago.
I'm usually inclined to shop used first, to save money, and have had good luck with my purchases so far, but I've bought new guns, too, which were not the high end models, and they are working well.