Powerbooks is again advertising a sale in their pasig warehouse on June 16-18, 2006. I went there the last time they had a sale and was not too impressed. If you ever went to a National Bookstore Cut Price Booksale, then you can understand the approximate breadth of the selection of books on sale and the percentage discount they were giving.
Anyway, even if I don't have high expectations, I will still probably try to go, it might be different this time. :)