Does anyone know how much it costs to travel to the Phi Phi Islands (Maya Bay) from Pennsylvania?

You should be able to find a fare for around $1200-1400 or so to Bangkok and from there you can fly round trip to Phuket or Krabi in Southern Thailand for around $100 r/t, from there you can take a boat to the Phi Phi Islands. There is no airport on Koh Phi Phi. Depending on the time of year you're going, the airfares from the US to Thailand can really vary, during off-peak times you might be able to find flights for $1,000 or less to Thailand, and some airlines in Asia do fly directly to Phuket without having to stop in Bangkok. Try kayak.com, travelocity.com and other sites to see what you can come up with. Air Asia, Nok Air and Thai Airways among others fly from Bangkok to Phuket and Krabi. Good luck.