It depends upon the rifle. Figure a 3-9X40mm Leupold scope is worth $175-$200. The rest depends upon the rifle. Like Pavomesa wrote, if it's a factory rifle it's a good deal. If it's a slopped up custom job, the resale market may be very limited.

If you keeping it too shoot, be aware that the 222 magnum ammo is very scarce unless you handload.