if you are leary about accepting the terms, I assume you will be using an attorney to help close the property? Ask him/her to review the terms and make sure they are in your best interest, but don't hesitate or you will either lose the house or get into a "one time, highest and best bidding war"
Banks will evaluate multiple offers at the same, especially if they are using transaction management software like res.net, homepath where agents and buyers can bid on home directly. Don't lose the house for a few thousand! And as is sale is common for REOs.
The good news is once you sign the banks contract/addendum, you are guaranteed honest and fair dealings. More than likely you will have 30-45 days to close. Banks are strict with their time tables . So, adhere to it.
Remember, while you are under contract with the bank, there could be 2-3 buyers itching to get your same deal.
I hope that helps!