It is not uncommon for a bank forclosure to require the buyer to pay both sides (2%) of the Pa. transfer tax.
This should have been stated in MLS. However, even after the bank accepts your offer they will require the buyer to sign several addendums spelling out the banks terms for purchase. Your Realtor should examine and explain ea. addendum to you or have an attorney review. Sounds like Wells Fargo is the bank who holds title to the property. With so many Real Estate deals going bad they want to make sure that you are qualified to purchase the property. Again, make sure you read and understand every addendum as each banks is different.