As for Pandora's Box - don't give up on it. Where are you going to spend all that gold anyway?
I've opened one PB every other level until the taking was enough to buy one for every level. More than a dozen PBs later (I've lost count) you may just hit the motherload. My personal best on one PB-loot is 3 orange items, one purple, and 2 greens - though still not enough to cover the cost of the box, but it just goes to show that it happens.
Loving this game. Thanks garin!
 "Elona Shooter"){kind=icon}
 "Bloons Tower Defense 4"){kind=icon}
 "Continuity"){kind=icon}
 "Monsters' Den: Book of Dread"){kind=icon}