According to the Trulia Rent vs. Buy Archives it is over 38% cheaper to buy than rent in most metro areas in Pennsylvania. They report that their studies find that buying remains cheaper in all 100 top Metro areas across the United States. However, mortgage rates have slowly risen which has slightly narrowed the gap. Buying vs. Renting is a hyper local comparison because each market is driven by different forces. The cost of buying in Detroit is less than Pennsylvania, and much less than California.
Check out Trulia's nationwide index: