WHEN will the cheapest airfares to London be out?

I am thinking of going to London from Los Angeles in early June 2004 for 3
weeks. Current search for airfares indicate London is about $509
(Continental). I also called all the consolidators that were advertised in the
L. A. TImes last week and they all said the summer fares were not out yet.
Question 1: Is $509 a good fare - when compared to future sales (that have not
come out yet)? To answer this, you would have to have knowledge about what the
lowest fares to London were in June, 2003. Thus, should I purchase this fare
now because it probably won't get much better?
Q2: I am a AA frequent flyer and am hoping to fly them so I can get miles and
use a $125 coupon I have. Did AA ever have any sales to London last year that
were around $600 or so.
Q3: Is there a site that might indicate what the lowest sale prices were last
year for a June 2003 trip like I want to take in 2004.
Q4: Has anyone used Priceline? I have for hotels with good success. I have
seen the Priceline Advice site but there is limited info for what I am looking
for. I guess I could try and see what happens?
Summary Question: Can anyone remember the lowest fares to London for early
June 2003?

Thanks, RIck