I picked up the first three albums for $10 each. I can't remember if UF was also $10 or $15.
The most expensive would be the CD+DVD+Book edition of HTDAAB. I forget how much that set me back. $45, perhaps? As far as regular editions go, I should have paid $31 for Zooropa, but a series of misunderstandings meant I actually picked it up for $20!
(All figures are Australian dollars.)