The pike won't take you to Gettysburg. It'll take you to Harrisburg. Harrisburg is about 35 miles north of Gettysburg. If you do take the pike you'll go through 2 long tunnels. If you take 30 you'd go over Tuscarora Mountain. I haven't driven 30 in the area in 40 years. I have been on 30 from Bedford to Breezewood in the last few years and that section is mostly new 4 lanes with not many grades. The climb starts east of Breezwood. I think the hills have passing lanes.
I'm adventurous. I would probably take 30. The increase in fuel costs would easily be offset my saving the turnpike fees.
-Tom