This was a 2007 model for episode 1 and was about £80 RRP at the time. I think it was over a thousand prices and 20 or so figures, although they are all droids so really it was 20 if the same...
Not really why it goes so high now from what I can tell it is well liked but doesn't do anything for me. Again with the new licence agreement a lot of the larger retired ships are bound to come around again as Lego like to produce 30ish SW models a year and mix up the six films. Although from 2015 we will be getting EP 7 models as well.
If you haven't found it already brickset.com is an essential site for lego collectors/fans, massive database for research very up on what is happening now and in the future on the forum there.