The Star Wars Saga Blu-Ray hits this Friday, and it seems that the price wars have not started yet. Amazon, Wal-Mart.com, and Target presently have the best price in the USA with $79.99 for all 6 films. And remember, the trilogy sets do not include the bonus feature discs.
When the Star Wars DVDs hit in 2004, there were price wars in the first six months with the trilogy as low as $14.99 at Wal-Mart in 2005. I don't expect that to repeat itself, but given the cutthroat nature of holiday sales it would be worth your while to save your receipts in case an ad match can save you $10 or even more.