Hi...I booked our airfare out of PHL for May 8-15...we are on US Air and I got $206 pp inc. taxes, etc. I booked in November, though, but using the US Air website. We fly out really early in the a.m. and come home late in the p.m. so that may have helped in the cost too.
We actually live in the Allentown area, and I couldn't find a decent deal from LVIA to save my life! I tried SEAL, but their times really stink.
From what I understand, Southwest is supposed to be flying out of PHL come May too. Try their website and see if they are flying out during your time.
We are also staying at POR....when will you be there??