It is quite obvious that the other responders have already corrected your vision of the ending date for the tax credit program, so I won't "pile on."
What I would like to suggest however, is this: because the end date for the tax credit program was not clear to you, it tells me that you are apparently not connected with a great local real estate agent in Philadelphia County. Any agent worth his/her salt would have informed you very clearly of the deadline you must meet in order to grab the $8000 (maximum) from Uncle Sam.
So may I suggest that you find an agent to represent you asap. Ask your friends and family if they can recommend an aent who works in the areas where you are interested in buying. Then make an appointment to meet with at least 2 to 3 of those recommended agents. Choose the one who makes you most comfortable, and who answers your questions with knowledge AND with respect. Then, and only then, can you take the next steps to learn what is possible for you in terms of purchase price points and mortgage programs. Your new agent can connect you to an experienced mortgage broker, your second-best friend!