So many variables, including your personal skill level.
.....but, with a similar rifle, I have been getting consistant 1.5" groups with factory Remington CoreLokt 150 grain cartridges. With my handloads, using a Sierra 150 grain Game King, I average a little less.
So far as scopes go, used is not a bad way to go. I keep an eye out on eBay, and other auction sites. Most folks don't abuse scopes, and a decent Leupold or Burris can be had for under $120.