Flight prices going up?

So I've been shopping for flights to Europe since I'm going there in October for two weeks to see my BFF from Sydney. A few weeks ago I found a flight on British Airways for $600-something, two weeks later it's almost 900$. I can believe this rise over the course of a few months, but over the course of two weeks? What will the price be for an economy seat on this flight when October the 3rd rolls around? $2000? Is flying from Philadelphia to London really that expensive? Someone is totally gouging us. Two years ago, whenI made my first trip to Europe, I bought my tickets for $666 the day before I left on Virgin Atlantic. I cant imagine what the price of a ticket to europe would cost if you bought it the day before the flight. It's outrageous. Luckily, the Europeans are better at offering cheaper products (H&M, Ikea, RyanAir). I found a roundtrip flight from London-Stockholm for free (with only the taxes to pay-roughly 20 $USD each way). So in total the flight costs 40 $USD. So Awesome.

But now I'm back to researching the fare fluctuations for international flights. Unfortunately, farecast.com doenst offer predictions for international flights. Do people even fly domestically? (maybe just not myself--I have the travel bug). I found a flight on AirINdia from JFK-Heathrow for 604$ and then its only another 4$ on a MEGABUS (megabus.com) from London-Manchester, where my best friend, Jemmima, lives. So there are ways to save, unfortunately it doesn't look like they're making it easier for Americans to get to Europe.

Looking for cheap travel for the fall

So I'm planning a trip to Europe in October for two weeks (Oct 6-20). I plan to leave on a Monday and return on a Monday. After researching fares and advice, many people advise to go on Tuesdays, Wed, and Saturdays. I've been messing around with my travel dates and I've found that it really doesnt matter what day you leave really, but it does matter what week you leave. Leaving a week earlier in September would up the price by 100$. I've used a lot of different cheap travel websites to look for tickets and the one that has given me the cheapest price by far has been tripadvisor.com. I found a roundtrip ticket from Philadelphia to London Heathrow on October 6 for 634$ compared to the 700$ + tickets i was finding on kayak.com, sidestep.com, expedia.com,cheaptickets.com. Plus it's on British Airways which I've heard some good things about (but never flown on) so hopefully it'll be a good flight.

Sidenote: I'm also a subscriber to Virgin Atlantic which has had some awesome deals in the past to London ( I went last minute to London roundtrip for 666$ about tow years ago and purchased the ticket the day before). Plus Virgin Atlantic is by far the best airline I have ever been on and I've been on A LOT (i.e. Qantas, American Airlines, American Eagle, United Airways, US Airways, JetBlue, VirginBlue, Jetstar, Airtran, Continental, and probably some others that I can't think of).